Gottlieb System 3
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1 Introduction
After many years of suffering with System 80, Gottlieb launched its System 3. Finally, they resolved most of the issues that had been plaguing the electronics for their games for years.
- Solenoids are now universally solid-state controlled (except the flippers). No more high voltage switches all over the playfield.
- The system supports 32 solenoids directly, an increase over the quaint 9 of System 80. Under playfield step-up transistors are gone!
- No edge connectors!
- The battery is lithium coin cell, and rarely leaks!
- A lamp matrix that can drive 96 lamps, nearly doubling the number of CPU-controlled lamps.
System 3 kept a few Gottlieb quirks:
- Ground problems remain, although they have been improved
- Under-playfield open-frame relays for control of flippers and general illumination remain
- +5V power supply essentially unchanged from 80B
Additionally, several common assemblies were redesigned:
- The nigh indestructible "fat boy" flipper was changed over for a new +50V pointy flipper that actually malfunctions.
- Gottlieb shrunk its two-spring drop target into a one-spring version with a smaller footprint, but that didn't play as well.
2 Game Listing
2.1 Alpha-Numeric
| Game Title | Game Number | CPU | Sound (Primary) | Sound (Auxiliary) | Display | Add'l boards | Notes |
|---|---|---|---|---|---|---|---|
| Lights Action Camera | 720 | MA-1360 | MA-886-720 | MA-1033 | MA-1361 | MA-1033 C12 is marked R5 & zero ohm jumpers used | |
| Silver Slugger | 722 | MA-1423 | MA-886-722 | MA-1294 | MA-1294 C12 is marked C12 & wire jumpers used | ||
| Vegas | 723 | MA-1423 | MA-886-723 | MA-1294 | |||
| Deadly Weapon | 724 | MA-1423 | MA-886-723 | MA-1294 | MA-886-723 is not a typo | ||
| Title Fight | 726 | MA-1423 | MA-886-726 | MA-1294 | |||
| Nudge-It | N102 | MA-1423 | MA-886 | MA-1294 | |||
| Bell Ringer | N103 | MA-1423 | MA-1294 | ||||
| Car Hop | 725 | MA-1423 | MA-1294 | ||||
| Hoops | 727 | MA-1423 | MA-1538 | MA-1294 | |||
| Cactus Jack's | 729 | MA-1423 | MA-1604 | ||||
| Class of 1812 | 730 | MA-1423 | MA-1629 | MA-1604 | MA-1604 Uses OKI chip at U1 | ||
| Surf 'n Safari | 731 | MA-1423 | MA-1629 | MA-1712 | MA-1712 Uses OKI chip at U1 | ||
| Caribbean Cruise | C102 | MA-1423 | MA-1712 | ||||
| Operation Thunder | 732 | MA-1423 | MA-1629 | MA-1712 | |||
| Bullseye | N10? |
2.2 Dot Matrix
| Game Title | Game Number | CPU | Sound (Primary) | Sound (Auxiliary) | Display | Add'l boards | Notes |
|---|---|---|---|---|---|---|---|
| Super Mario Bros | 733 | MA-1423 | MA-1629 | MA-1770 | DMD | ||
| Super Mario Bros: Mushroom World | N105 | MA-1423 | MA-1629 | MA-1770 | DMD | ||
| Cue Ball Wizard | 734 | MA-1423 | MA-1629 | MA-1770 | DMD | ||
| Street Fighter II | 735 | MA-1934 | MA-1629 | MA-1770 | DMD | ||
| Tee'd Off | 736 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Wipe Out | 738 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Gladiators | 737 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| World Challenge Soccer | 741 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Rescue 911 | 740 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Freddy: a Nightmare on Elm Street | 744 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Shaq Attaq | 743 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Stargate | 742 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Frank Thomas' Big Hurt | 745 | MA-1934 | MA-1629 | MA-1770 | DMD | Uses a different A17 diode board. 8 positions of 1N4148 diodes are replaced with 1N4008 diodes for # 86 lamps | |
| Waterworld | 746 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Strikes N Spares | N111 | MA1934 | None | MA-2112 | DMD | Uses an MA-2178 display board for driving two DMDs instead of MA-1739 | |
| Mario Andretti | 747 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Barb Wire | 748 | MA1934 | MA-1629 | MA-1770 | DMD | ||
| Brooks & Dunn | 749 | None | None | None | None | Game never went into production |
3 Documentation
3.1 Manuals
A game manual. Pinball Resource has many factory originals still left, and reprints of everything else.
3.2 Parts Catalogs
Parts catalogs can also be useful, which include part numbers (helpful for purchasing parts online), exploded views of assemblies (helpful to see how the assemblies are put together), and board layouts & schematics, and diagrams for controlled lamp, solenoid, and rubber locations. Gottlieb tended to publish a lot of game-specific information in parts catalogs. These have exploded diagrams of assemblies, particularly in earlier games that had the thinner, much less helpful manuals. Playfield parts, lamps, and switches are all diagrammed out. These also have collected service bulletins. Reprints are available from Pinball Resource.
Note that there were no parts catalogs released after the 1995 parts catalog. The last game to appear in that parts catalog was Freddy, A Nightmare on Elm Street.
| Catalog | Cover | Source | Games | Notes
|
|---|---|---|---|---|
| 1992 Parts Catalog | PBResource.com | Covers 80B games starting from Gold Wings and the first 9 System 3 titles (games #706-#730): Lights Camera Action, Silver Slugger, Vegas, Deadly Weapon, Car Hop, Hoops, Cactus Jack's, and Class of 1812. | ||
| 1995 Parts Catalog | PBResource.com | Covers System 3 titles (games #731-#740): Surf 'N Safari, Operation Thunder, Super Mario Bros, Super Mario Bros Mushroom World, Cue Ball Wizard, Street Fighter II, Tee'd Off, Gladiators, Wipe Out, World Challenge Soccer, Rescue 911, and Freddy A Nightmare on Elm Street |
3.3 Theory of Operation
There are no formal service manuals for the System 3 platform (unlike what's available for System 80.) Starting with System 80B "Chicago Cubs", Gottlieb included a "Theory of Operation" section within each game manual. This section only detailed the differences between 80A and 80B. With System 3, Gottlieb continued this section and expanded it over time as the games evolved. This section includes a block diagram and an overview about all the major boards in the system. The manuals in later games expanded the block diagram, included an interconnection diagram, and covered more boards in the system. Some of the boards covered in the manual of later games were always there like the A15 sensor board, and some were added over time like the A8 display controller and the A25 optical interface. These six pages provide the best documented overview from the factory of the System 3 platform available today.
4 Technical Info
4.1 The System 3 Board Set
The following are boards that can appear in the backbox of Gottlieb System 3 games. These may vary slightly from game to game. The most dramatic difference is between the alphanumeric games and the DMD games.
Gottlieb® System 3 Board Set - Alphanumeric Games
Gottlieb® System 3 Board Set - DMD Games
Gottlieb® System 3 5v Power Supply
Gottlieb® System 3 MA-1366 Aux. Power Supply (Early Version)
Gottlieb® System 3 MA-1744 Aux. Power Supply (Caribbean Cruse only)
Gottlieb® System 3 MA-1605 Aux. Power Supply
Gottlieb® System 3 MA-1772 Aux. Power Supply
Gottlieb® System 3 MA-1360 CPU Board (Version 1)
Gottlieb® System 3 MA-1423 CPU Board (Version 2)
Gottlieb® System 3 MA-1934 CPU Board (Version 3)
Gottlieb® System 3 MA-1358 Driver Board
Gottlieb® System 3 MA-886 Sound Board
Gottlieb® System 3 MA-1629 Sound Board
Gottlieb® System 3 MA-1604 Aux. Sound Board
Gottlieb® System 3 MA-1712 Aux. Sound Board
Gottlieb® System 3 MA-1770 Aux. Sound Board
Gottlieb® System 3 MA-2112 Aux. Sound Board (Note: AROM1 and AROM2 Sockets should be populated)
Gottlieb® System 3 MA-1294 Aux. Sound Board
Gottlieb® System 3 MA-21739 Dot Matrix Controller Board
Gottlieb® System 3 MA-2178 Dot Matrix Controller Board (Note: Strikes 'n Spares only)
Gottlieb® System 3 Alphanumeric Display Board
4.2 System 3 Satellite Boards
Gottlieb® used many of the boards pictured below throughout the production of System 3 games.
- Gottlieb® System 3 Satellite Boards
Gottlieb® System 3 MA-1851 Tournament Board 
Gottlieb® Sys3 MA-1448 Diode Board 
Gottlieb® System 3 MA-2136 Diode Board, peculiar to Frank Thomas' Big Hurt 
Gottlieb® System 3 MA-1334 Flipper Sensor Board 
Gottlieb® System 3 MA-1558 Opto Board 
Gottlieb® System 3 MA-1925 Quad Opto Board 
Gottlieb® System 3 MA-1745 Filter Board 
Gottlieb® System 3 MA-2160 Filter Board 
Gottlieb® System 3 MA-1722 Auxiliary Driver Board 
Gottlieb® System 3 MA-1417 Resistor Board 
Gottlieb® System 3 MA-1461 Resistor Board 
Gottlieb® System 3 MA-1524 Resistor Board
4.3 The Wire Coloring Code
Unlike every other pinball manufacturer, which adopted a two-color wiring code system, Gottlieb® used three colors. Most wiring in a Gottlieb® game used a white base color, which is the wire's insulation color, and three "striped" traces on each wire. I state most cases, because there is one wire which only use one color. The white ground wires used in System 3 games with no trace at all. Below is the Gottlieb® color chart.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
|---|---|---|---|---|---|---|---|---|---|---|
| Color | Black | Brown | Red | Orange | Yellow | Green | Blue | Purple | Gray | White |
Does the color chart look familiar? Well, if you have an electronics background, it should. The Gottlieb® wire code system is the same as the resistor color coding system.
Here are some examples of the color coding system. The color wire code for switch / lamp strobe line 0 is 400. 400 would be a white insulated wire with a yellow trace and two black traces, or commonly referred to as a yellow-black-black wire. The ground lines are 0 which is just plain white with no traces.
4.4 Connectors and Connector Designations
Gottlieb® System 3 machines use Molex MiniFit Jr connectors. There are a handful of Molex .156" header connections too (primarily the sound and amplification boards), but the majority of connectors are MiniFit Jr. MiniFit Jr Connector housings and pins can be purchased from GPE or Mouser.
All Gottlieb® System 3 machines have a common naming convention for all of the connectors in the game. A specific connection uses two parts - a prefix and a suffix. The prefix is the board number or an inline wire junction, and the suffix is the connection on the board or a sequential wire junction number. When referencing a specific connector pin within a housing, a dash follows the connection number. For example, the connector pin for the slam switch signal on the CPU board is A1J5-11. The coin door connection used on Shaq Attaq is A10P1 and A10J1 - the connector pin for the slam switch on the coin door is A10P1-5.
The following boards are assigned the same numbers throughout the System 3 platform.
- CPU Board - A1
- +5VDC Power Supply - A2
- Driver Board - A3
- Sound Board - A6
There are several other board designations used, however, they are different between games which use an alphanumeric display and a dot matrix display (DMD).
4.5 Switch Matrix
The Gottlieb® System 3 switch matrix consists of a maximum of 96 switches. There are a total of 12 switch strobes and 8 switch returns. The strobe lines start at 0, increment consecutively to 9, and two more strobes are added named A and B respectively. The return lines start with 0 and end with 7. Typically but not always the case, if a game has opto switches and / or Smart Switches, they are located on the higher strobe lines. Strobe A and B are the most common strobe lines where an optic switch or Smart Switch would reside on the switch matrix. The notation of "**" on the switch matrix chart denotes that the switch used is a Smart Switch. It is extremely rare, if it even occurs, where every switch in the matrix is used on any one System 3 game. Gottlieb® rarely used the System 3 switch matrix to its full capacity.
Just like the System 80 switch numbering system, the System 3 switch numbers have the same naming convention. With Gottlieb® System 3 switches, the first number of the switch is its strobe number, while the second number is the switch's return number. An example would be switch 54. Switch 54 is located on strobe 5 and return 4 of the switch matrix.
There is one aspect of the Gottlieb® System 3 switch matrix which makes it markedly different from most other manufacturers. The System 3 switch strobe lines and the lamp strobe lines are shared. Due to this design, all switch and lamp strobe signals originate at connector A3J3 of the driver board, and all switch returns are connected to A1J5 of the CPU board. Because of the shared strobe design, this can make troubleshooting a switch matrix strobe issue more difficult at times. The only other manufacturer that did something similar before Gottlieb® was Game Plan. On these machines the switch and display strobes are shared. The difference is that the signals were split out to four different connectors on the MPU board.
Once again, the now normally open slam switch is not on the switch matrix. Equally, the test and tilt switches have moved off of the switch matrix, and have become dedicated switches.
| Strobe 0 (A3J3-9) |
Strobe 1 (A3J3-10) |
Strobe 2 (A3J3-11) |
Strobe 3 (A3J3-12) |
Strobe 4 (A3J3-13) |
Strobe 5 (A3J3-14) |
Strobe 6 (A3J3-6) |
Strobe 7 (A3J3-5) |
Strobe 8 (A3J3-4) |
Strobe 9 (A3J3-3) |
Strobe A (A3J3-2) |
Strobe B (A3J3-1) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Return 0 (A1J5-8) |
00 |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
A0 |
B0 |
| Return 1 (A1J5-7) |
01 |
11 |
21 |
31 |
41 |
51 |
61 |
71 |
81 |
91 |
A1 |
B1 |
| Return 2 (A1J5-6) |
02 |
12 |
22 |
32 |
42 |
52 |
62 |
72 |
82 |
92 |
A2 |
B2 |
| Return 3 (A1J5-5) | 03 |
13 |
26 |
33 |
43 |
53 |
63 |
73 |
83 |
93 |
A3 |
B3 |
| Return 4 (A1J5-4) |
04 |
14 |
24 |
34 |
44 |
54 |
64 |
74 |
84 |
94 |
A4 |
B4 |
| Return 5 (A1J5-3) |
05 |
15 |
25 |
35 |
45 |
55 |
65 |
75 |
85 |
95 |
A5 |
B5 |
| Return 6 (A1J5-2) |
06 |
16 |
26 |
36 |
46 |
56 |
66 |
76 |
86 |
96 |
A6 |
B6 |
| Return 7 (A1J5-1) |
07 |
17 |
27 |
37 |
47 |
57 |
67 |
77 |
87 |
97 |
A7 |
B7 |
4.6 Lamp Matrix
Finally, Gottlieb® employed a lamp matrix starting with the System 3 platform. The System 3 lamp matrix consists of a maximum of 96 controlled lamps. There are a total of 12 lamp strobes and 8 lamp returns. The strobe lines start at 0, increment consecutively to 9, and two more strobes are added named A and B respectively. The return lines start with 0 and end with 7. It is extremely rare, if it even occurs, where every lamp in the matrix is used on any one System 3 game. Gottlieb® rarely used the System 3 lamp matrix to its full capacity.
Just like the System 3 switch numbering system, the lamp numbers have the same naming convention. The first number of the lamp is its strobe number, while the second number is the lamp's return number. An example would be lamp 62. Lamp 62 is located on strobe 6 and return 2 of the lamp matrix.
As mentioned in the switch matrix section, there is one aspect of the Gottlieb® System 3 lamp matrix which makes it markedly different from most other manufacturers. The System 3 lamp strobe lines and the switch strobe lines are shared by the same lines. All lamp and switch strobes originate at connector A3J3 of the driver board, and all lamp returns are connected to A3J4 of the driver board. Troubleshooting a lamp matrix problem is less of an issue than troubleshooting a switch matrix issue. The only other manufacturer that did something similar before Gottlieb® was Game Plan. On these machines the switch and display strobes are shared. The difference is that the signals were split out to four different connectors on the MPU board.
There are some odd instances where standard 44 / 47 lamps are not located on the lamp matrix for some odd reason. A particular game which comes to mind is Wipeout. The three pop bumper lamps used in Wipeout are controlled by solenoid drivers. The voltage for these lamps originate from the solenoid bus, and is reduced from 20vdc to ~6vdc via a remotely mounted power resistor board under the playfield. It is uncertain why Gottlieb® did this.
| Strobe 0 (A3J3-9) |
Strobe 1 (A3J3-10) |
Strobe 2 (A3J3-11) |
Strobe 3 (A3J3-12) |
Strobe 4 (A3J3-13) |
Strobe 5 (A3J3-14) |
Strobe 6 (A3J3-6) |
Strobe 7 (A3J3-5) |
Strobe 8 (A3J3-4) |
Strobe 9 (A3J3-3) |
Strobe A (A3J3-2) |
Strobe B (A3J3-1) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Return 0 (A3J4-1) |
00 |
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
A0 |
B0 |
| Return 1 (A3J4-2) |
01 |
11 |
21 |
31 |
41 |
51 |
61 |
71 |
81 |
91 |
A1 |
B1 |
| Return 2 (A3J4-3) |
02 |
12 |
22 |
32 |
42 |
52 |
62 |
72 |
82 |
92 |
A2 |
B2 |
| Return 3 (A3J4-4) | 03 |
13 |
26 |
33 |
43 |
53 |
63 |
73 |
83 |
93 |
A3 |
B3 |
| Return 4 (A3J4-6) |
04 |
14 |
24 |
34 |
44 |
54 |
64 |
74 |
84 |
94 |
A4 |
B4 |
| Return 5 (A3J4-7) |
05 |
15 |
25 |
35 |
45 |
55 |
65 |
75 |
85 |
95 |
A5 |
B5 |
| Return 6 (A3J4-8) |
06 |
16 |
26 |
36 |
46 |
56 |
66 |
76 |
86 |
96 |
A6 |
B6 |
| Return 7 (A3J4-9) |
07 |
17 |
27 |
37 |
47 |
57 |
67 |
77 |
87 |
97 |
A7 |
B7 |
4.7 Power Supplies
All System 3 games use at least two power supplies, and in the case of DMD games, three total.
The first power supply is for the +5VDC logic voltage. This power supply is essentially the same as the System 80B power supply, except the connections are different, (.156" header pins vs. MiniFit Jr connectors). The System 3 power supply has practically the same set of issues as the System 80B power supply. First, it does not have a crow bar circuit. If the LM338K voltage regulator fails, and fails whereas the voltage increases drastically, it can destroy electronic components on the other circuit boards. Secondly, heat is still dissipated throughout the board. Finally, the adjustable potentiometer (pot) on the power supply is prone to failure, due to dirt, dust, and contaminants. The latter problem can easily be overcome, and will be addressed in the Recommended Repairs for the System 3 Power Supply Board section below. Connectors on the power supply are not much of an issue if at all. Although, if the board is being taken out of the game for repairs, inspect the solder connections.
The second power supply is the auxiliary power supply. This board is used in earlier System 3 games, where a small auxiliary sound board is used. The auxiliary power supply is not much different from the System 80B auxiliary power supply used in games from Bad Girls and newer. The System 80B board uses a 1K ohm, 2 watt resistor at R8. The System 3 board uses a 330 ohm 1/2 watt resistor at that location.
The primary functions of this board are to provide amplifier power to the sound boards and amplify the audio output. A breakdown of the voltages supplied by the auxiliary power supply are as follows:
- -12 VDC
- +12 VDC
The next power supply is the System 3 2nd generation auxiliary power supply.
Finally, the last board is not actually a power supply. It is the System 3 DMD controller board. The reason it is being discussed here in part, is because this board is actually split into two sections. The upper portion of the board generates the necessary voltages to power the dot matrix display, while the lower portion handles all of the logic level responsibilities. The voltages which the DMD controller board generates are:
- +12 VDC
- +62 VDC
- -100 VDC
- -112 VDC
Additionally, the board passes +5 VDC from the power supply to the DMD display.
4.8 CPU Board
There are several variations of CPU boards used with the System 3 boardset. However, all of the boards are essentially the same and interchangeable with only minor modifications necessary. MA-1360 was the first board, MA-1423 was the second, and MA-1934 was the third. The differences between the first two boards are subtle at best. The most notable difference between the first and second board versus the third board is the size of the RAM used at position U3. The earlier boards used a 6116 2k x 8 static RAM chip, while the later boards, (starting with Street Fighter II), used a 6264 8k x 8 static RAM chip. Even though earlier CPU boards use a RAM chip which is smaller in both memory and physical size, the amount of through holes on the circuit board at U3 allow for the installation of a 6264 chip.
4.8.1 CPU Board Jumper Settings
All System 3 CPU boards have 4 jumper positions located just above and between chips U2 and U3. Jumpers 1 and 2 are set according to the memory size of the GPROM used at position U2. If a 27256 EPROM is used at U2, jumper 2 must be installed and jumper 1 removed. Likewise, if a 27512 EPROM is used at U2, jumper 1 must be installed and jumper 2 removed. Jumpers 3 and 4 are set according to the memory size of the static RAM used at position U3. If a 6116 is installed at U3, jumper 3 must be installed and jumper 4 removed. If a 6264 (or 5168) is installed at U3, jumper 4 must be installed and jumper 3 removed.
The following table summarizes these jumper settings.
| Configuration | Jumper 1 | Jumper 2 | Jumper 3 | Jumper 4 |
|---|---|---|---|---|
| 27256 at U2 | ||||
| 27512 at U2 | ||||
| 6116 at U3 | ||||
| 6264 at U3 |
4.9 Driver Board
The Gottlieb® System 3 platform used the same MA-1358 driver board for all the System 3 games. The driver board is capable of driving up to 25 solenoids by using 12N10L or IRL530 N-Channel MOSFETs. There was a period when this board used BUZ72 N-Channel MOSFETs, instead. Relays and flash lamps are categorized as solenoids, and are controlled by these same 25 MOSFETs. 25 controlled solenoids was a huge increase from the total of 9 controlled solenoids, which the System 80B driver board could handle. However, some later System 3 games employ the use an auxiliary driver board to drive 8 more devices.
The driver board also drives the lamp matrix (strobes and returns). An oddity of the System 3 platform is that the lamp and switch strobes share the same circuitry and wiring (connected A3P3 on the driver board). Gottlieb® presumably did this to reduce manufacturing costs. However, having shared strobe lines can make troubleshooting a little more difficult than having "standard", discrete lamp and switch matrices. The lamp / switch strobes are driven by 12P06 or IRF9531 P-Channel MOSFETs. The lamp returns use the same MOSFETs as the solenoids.
4.10 Auxiliary Driver Board
With some later System 3 games, (Street Fighter II, Stargate, etc.), an auxiliary driver board was added. This driver board has the capability of controlling up to 8 discrete devices. Each device is driven by one of eight 12N10L or IRL530 N-Channel MOSFETs. These are the same style of MOSFET used to drive the solenoids, relays, and flash lamps on the main driver board. Like the main driver board, there was a period when this board used BUZ72 MOSFETs.
Typically, the aux. driver board is used to drive 8 flash lamp circuits. In some instances, each drive controls up to 2 flash lamps. Even though flash lamps located on the playfield can be controlled by this board, the location of the aux. driver board is normally on the backside of the backbox lamp insert panel. It is assumed this location was chosen, because all of the input signals for the board derive directly from the CPU board. These signals originate from the 65C22 VIA (U5) on the CPU board, and are passed from the formerly unused connection at A1J7 on the CPU.
4.11 Sound Boards
Gottlieb carried over the same basic sound architecture from System 80B to System 3. In fact the base PCB is the same for late 80B sound boards and System 3. How the boards are populated is what distinguishes them. There are three sound board types used in System 3 machines: MA-886, MA-886-XXX and MA-1629.
4.11.1 MA-886
There is only one System 3 game that uses the fully stuffed MA-886 sound board (pictured at left) - the oddball Nudge-It. The board is completely populated (including the two AY-3-8913 programmable sound generators) with the exception of the S4 position, used in other versions to connect the base board to an auxiliary sound board. All other System 3 games use some type of auxiliary sound board.
4.11.2 MA-886-XXX and MA-1629
Games that use one of the small, non-ROM enabled auxiliary sound boards (MA-1033 or MA-1294) use the sound board version MA-886-XXX where the XXX is the three digit game number. In the picture at left, you see a MA-886-722 which means this board is out of a Silver Slugger. These MA-886-XXX boards have R58 - a 10K 1/4W resistor - installed. Starting with Cactus Jack's, Gottlieb used the larger ROM-enabled auxiliary sound boards (MA-1712, MA-1770, or MA-2112) and the sound board for these games is the MA-1629. This board does not have R58 stuffed (see picture at right). Removing R58 from a MA-886-XXX will allow the board to be used in games from Cactus Jack's to Barb Wire. Adding R58 to a MA1629 will allow the board to be used in games from Caribbean Cruise to Hoops (except Nudge-It). Also of note, two ceramic capacitors at the top edge of the board, C14 and C22 (33pf, 100v) that are part of the timing circuit, are shown in all System 3 schematics except Nudge-It as "optional", and are sometimes stuffed and sometimes not stuffed.
4.12 Auxiliary Sound Boards
The MA-1033 auxiliary sound board was used in System 80B games including: Bad Girls, Big House, and Hot Shots, as well as one System 3 game: Lights, Camera, Action.
The MA-1294 auxiliary sound board was only used in one System 80B game, Bone Busters, as well as System 3 games including: Hoops, Bell Ringer, Silver Slugger, Car Hop, Deadly Weapon, Title Fight, and Vegas.
Starting with Cactus Jack's, Gottlieb® began using a new auxilary sound board which contains the Oki MSM6295 - a four-channel mixing ADPCM voice-synthesis chip. From the datasheet: "The MSM6295 can access an external ROM, where speech or sound effects are stored" - thus the reason for the two ROM sockets on the board. Gottlieb® used the MSM6295 for speech call-outs and music and the YM2151 for sound effects. If you dump the ROM files from these boards you will see that the contents are simply raw 8KHz ADPCM files which can be played back through a sound editing program such as Audacity. Starting with Cactus Jack's the two ROMs are both 27010s. By the time Gottlieb® finished with Barb Wire there was one 27040 ROM and one 27020 ROM installed in the MA-1770. The MA-1604 auxiliary sound board here was used in the System 3 games Cactus Jack's and Class of 1812.
The MA-2112 Auxiliary sound board was used in the System 3 game Strikes 'N Spares.
The MA-1712 Auxiliary sound board was used in the System 3 games Caribbean Cruise, Operation Thunder, and Surf N' Safari.
The MA-1770 Auxiliary sound board was used in the System 3 games Super Mario Bros, Super Mario Bros Mushroom World, Cue Ball Wizard, Street Fighter II, Tee'd Off, Gladiators, Wipe Out, Rescue 911, Stargate, Shaq Attaq, Freddy, Big Hurt, Water World, Mario Andretti, and Barb Wire.
4.13 Display Boards
4.13.1 Alphanumeric Displays
Starting with Lights, Camera, Action and ending with Operation Thunder, System 3 games used an alphanumeric display prior to making the switch to DMD displays starting with Super Mario Brothers. While at first glance the System 3 display looks similar to the System 80B alphanumeric display, the only similarity it shares with that display is the 2x20 vacuum fluorescent alpha-numeric display glass used with the last 4 System 80B games. The complete displays are not interchangeable between these two systems.
A separate alphanumeric display was used in the Carribean Cruse cocktail pinball machine.
Gottlieb System 3 Alphanumeric displays require the following voltages for proper function:
- +5VDC - which powers the logic on the board.
- 8.6VAC - which powers the display filaments
- 36VAC - which is rectified on the display board through CR1-CR4 to produce +47VDC. This is the voltage which powers the 6118 segment drivers.
- 9.1VDC - this is the bias voltage for the display filaments. This is derived from the center tap on the 8.6VAC supply and goes through the zener diode at VR1.
4.13.2 Dot Matrix Displays
Starting with Super Mario Bros. in 1992, Gottlieb® System 3 games used the industry standard 128 x 32 dot matrix display (DMD). All System 3 games thereafter used a DMD, although, this was not the case with the System 3 "mini" pinball / redemption game Bullseye, which still used alphanumeric Futaba displays. Presumably, this was done to keep production costs down.
Gottlieb® System 3 DMDs require the following voltages for proper function:
- +5 VDC
- +12 VDC
- +62 VDC
- -100 VDC
- -112 VDC
4.13.3 Dot Matrix Display Controller Board
System 3 dot matrix displays (DMD) are powered and controlled by a display controller board located in the backbox. Looking at the board's physical layout, the board is essentially split into two sections. The upper portion of the board rectifies and outputs all of the high voltage values necessary for a DMD to function. The lower portion of the board handles all of the logic and data for the display.
The high voltages generated by the display controller board are:
- +62 VDC
- -100 VDC
- -112 VDC
Although not really considered high voltage, +20 VDC is regulated down to +12 VDC on this board for the DMD. Additionally, the board passes +5 VDC from the power supply to the DMD display.
4.14 Flippers
Like all the other solenoids used in a System 3 game, Gottlieb® beefed the power up to 48VDC versus the 24VDC of former Gottlieb® platforms. Equally, the flipper assembly was completely redesigned with a more "modern" flipper bat, and completely different mechanicals. Parts for the System 3 flippers are not backward compatible with any previous Gottlieb® platforms, except the last System 80B game, Bone Busters, Inc. This is partially due to the flipper coil having a larger "footprint" than older flipper coils.
Gottlieb® System 3 games used a slightly different approach to enable the flippers. Well, slightly different from other manufacturers, but the same as all previous Gottlieb® systems. The difference being that Gottlieb® did not use an encapsulated flipper relay on a circuit board. Nor are System 3 flippers directly enabled by a transistor or transisors, like some folks are led to believe. Instead, an open cage relay was used. Power to the flippers is enabled by a single switch pair on the game over (Q) relay. The same switch pair powers other coils on the playfield. The Q relay is typically located on the bottom of the cab on the right between the transformer panel and the power module, if a power module is used. The other relays used for tilt (T) and lampbox GI illumination (A) are normally banked with the Q relay. Like any other relay or coil, the Q relay is enabled by a MOSFET on the driver board.
Likewise, System 3 games used high powered contacts on the flipper cabinet switches. This is essentially the same design used on all previous Gottlieb® solid state games. Because a solid state flipper design was never implemented, 48v passes through these contacts.
4.14.1 Flipper Sensor Board
Another thing new to System 3 is the use of a flipper sensor board. The purpose of the sensor board is to determine when a flipper coil was enabled via the flipper cabinet switch, convert the 48v signal to a manageable voltage for the switch matrix via an MCT6 optocoupler, and then send the signal back the return line of the switch matrix. Gottlieb® games had no way of determining this distinction before, unless a secondary switch from the switch matrix was placed on the switch stack with the flipper EOS switch. The flipper sensor board inputs are wired with 48v, and the left and right flipper coils' lug with the non-banded side of the diode. The flipper cabinet switches are wired to this same flipper coil lug, and when closed, complete the circuit to ground.
4.15 Smart Switches
Starting with Operation Thunder, Gottlieb® started using Smart Switches. Smart Switches are a design developed in-house by John Buras and used to combat against common switch failures from moisture or contaminants. These switches are unlike traditional leaf switches or microswitches, because they do not use contacts which physically meet for a switch closure to occur. Instead, Smart Switches use a piezo film sensor to detect switch closures.
+++Add more operational technical detail later+++
Smart Switches are used in varying applications, such as lane rollovers, pop bumpers, and stationary (stand up) targets. In most instances, these switches hold up quite well. The exception are the stationary targets, which have a tendency to fail the most. Some Smart Switches are still available; however, the many different configurations, especially with stationary targets, are becoming limited. On the plus side, a standard, stationary target can be used in place of one which used a Smart Switch. Likewise, any other Smart Switches can be replaced with standard leaf switches or microswitches.
Smart Switches are unfortunately non-adjustable. When there is a switch failure, there really is nothing which can be done, except replacement of the switch.
4.16 Accessing Bookkeeping, Settings, and Test Modes
Older System 3 games have a single red push button located inside the coin door on a mounting bracket next to the volume control pot. This red button is used to access bookkeeping, settings, and get into game tests.
Starting with Cue Ball Wizard, Gottlieb® System 3 games started using a "tournament board" to access bookkeeping, settings, and get into game tests. Gottlieb® refers to it as the "game controls board", although it is more commonly referred to as the "tournament" or "test" board. The tournament board is located just inside the coin door on the left side. Pressing the yellow (or sometimes white) button on the board once, and waiting approximately 3 seconds, will allow an individual to view a menu on the DMD, and scroll / select via the flipper cabinet buttons.
After a brief display showing how to control the menu with the flipper buttons, the menu display shown at left will appear. There is only one way to set a Gottlieb® System 3 to free play, and that is through the tournament setting, and leaving the game in tournament mode. Note that if the "door open" switch malfunctions and doesn't indicate to the MPU that the switch is open (see below), these tournament options will not be shown. The game software requires the door open switch to indicate "open" before showing these options.
4.17 Coin Door Switches
Later System 3 games, primarily dot matrix games, have two switches located on brackets inside the coin door on the right. The upper, horizontally placed switch is the "open door" switch. This switch is part of the switch matrix, and alerts the game when the coin door is open.
The lower vertically placed switch is a "kill" switch. This switch is an interlock switch, which "kills" all power (110v) to the game when the coin door is opened. Since it is an interlock style switch, it can either be depressed (when the coin door is closed), or it can be extended outward to turn the switch on. To extend the switch to the on position when the coin door is open, grasp the switch, and gently pull it out to the lock position.
4.18 ROMs
System 3 games have a particular naming scheme for the ROMs. Depending upon the machine and when it was built, you may find only a subset of the ROMs listed below in your machine.
- GPROM: Game Program ROM. Responsible for the game rules/code. This ROM may be either a 27256 or a 27512 and is always found on the MPU board at U2.
- YROM: Sound ROM. Responsible for sound effects as well as controlling the aux sound board and starting the D section of the sound board. This ROM is found on the sound board in the "Y" section at K3. While the sound board is able to accommodate different sizes of ROMs, this ROM is almost always a 27256.
- DROM: Sound ROM. Responsible for sound effects, processing inputs and controlling output to the opamps. This ROM is found on the sound board in the "D" section at K2. While the sound board is able to accommodate different sizes of ROMs, this ROM is almost always a 27256.
Every System 3 game will have the above three ROMs.
- AROM: Auxiliary sound ROM(s). Responsible for speech and background music/sounds. There are two sockets for AROM chips, both of which may or may not be utilized depending on the game. They are labeled AROM1 and AROM2 and are found at U4 and U5 of Aux Sound Boards MA-1604, MA-1712, MA-1770 and MA-2112. These ROMs vary in size from 27010 to 27040. NOTE: With the exception of Caribbean Cruise, games before Cactus Jack's did not use AROMs.
- DSPROM: Display ROM. Responsible for the display contents on a DMD. This ROM may be either a 27020 or 27040. It is always found on the display board at U3. NOTE: Games before Super Mario Bros. which had AN displays do not have the DMD controller and therefore do not have a DSPROM.
5 Problems and Solutions
5.1 Over Fusing
Over fusing or bypassing fuses can never result well, if there is a dead short in the circuit. Fuses are used to protect the machine and you! Some possible results due to over fusing may be burnt or melted connectors, burnt or melted wires, burnt drive transistors which can result in holes burned through circuit boards or worse, a fire can start. Fuses were sized by the designers of the games, and fuse values and types intended to be installed in specific circuits should not be changed from what the schematics / manual recommends.
Plus, the repairs involved in rectifying the aftermath of over fused or bypassed fuses can be costly, if they can be done at all.
5.2 Connectors
5.3 Ground Upgrades
Even though Gottlieb® got most everything else right with System 3, it was plagued with ground issues just like every other Gottlieb® platform. The System 3 ground connections at the transformer panel are very similar to some System 80Bs, where all of the ground wires are plugged into a small board. This board is fastened to the side of the transformer panel's metal chassis. The purpose of the ground upgrades is to remove the ground board, which takes one more potentially failed connection out of the equation. The grounds will then be secured directly to the transformer chassis via solderless eyelet crimp connectors.
These ground upgrades were initially recommended and published on the Internet by John Robertson of John's Jukes. Below are the steps to properly upgrade the grounds.
- Gottlieb® System 3 Ground Upgrades
The ground connection board which was fastened to the back side of the transformer panel's metal chassis. 
The side of the transformer panel chassis where the ground bus board was connected. In addition to the ground connections coming from the playfield, backbox, and driver board, there is a ground connection on the transformer panel too. It is not necessary to remove the transformer panel from the game. This panel was being serviced on the bench. Note that the transformer panel is typically zinc coated metal. This unit was painted, which is not the norm. 
The three ground connector plugs are cut off from the incoming ground wires. All the ground wires are to have their insulation stripped back longer than usual - approximately 3/4". 
Solderless ring terminals will be crimped onto the ground wires. The connections used in this particular application are Motormite #85443. Motormite brand does not have to be used. This particular brand and part number are mentioned due to the difficulty in finding the correct connectors to use. Most common ring terminals have a #10 or larger screw eyelet, which will not work effectively, if the eyelets are fastened to the side of the transformer panel chassis. The ring terminals shown here are made for #12-#10 gauge wire with an eyelet for a #8 screw. #12-#10 terminals with a ring size for a #6 screw / stud are better suited, but more difficult to readily source. 
The ground wires are then twisted and crimped together, From experience, a maximum of 4 larger gauge wires can be crimped in one connection. Lighter gauge wires can be paired with or without heavier gauge wires, and the maximum effective grouping of wires increases slightly. Keep wires which were common to one connector together (driver board ground wires, playfield ground wires, and backbox ground wires). In doing this, future disassembly will be possible, should any of the individual wiring harnesses need attention. 
Unscrew the transformer panel from the bottom of the cabinet, and turn it on its side. This will allow better access to secure the ring terminals to the side of the chassis. The screws removed from the ground bus board can be reused. Additional #6-32 screws may be needed. Equally, some of the holes in the side of the chassis may need to be tapped, if more than 2 holes are used. 
The transformer is fastened to the bottom of the cabinet with the ground upgrades in place. 
Pay close attention when securing the transformer panel to the cabinet. One screw mount, typically the back left mount, (as viewed from the coin door), will have green-yel ground wires attached to an eyelet. This eyelet connection *must* be secured to the transformer panel. Otherwise, there will not be an earth ground connection for the transformer panel.
An optional place to secure the ground wire eyelets is to the back left screw, which secures the transformer panel to the cabinet. In this case, the more common solderless crimp connectors for #12-#10 gauge wire and a #10 screw eyelet can be used. Keep in mind that the ground wires for the transformer panel will still need a crimp terminal with a smaller eyelet. These wires are extremely short, and cannot be secured anywhere else, unless a hole is drilled and tapped on the top side of the transformer panel chassis. If drilling anywhere into the transformer panel chassis, be careful not to drill into the wiring located underneath the panel.
5.4 Power Problems
5.4.1 Line Voltage
This section pertains to later System 3 games which use a power module. The power module is located on the bottom of the cabinet just inside the coin door to the right hand side.
If attempting to power on a game, and the game shows no signs of life, there are several common possibilities causing this issue. They are:
- The coin door interlock ("kill") switch
- The F1 line fuse
- The F2 primary power fuse
CAUTION!!! THE FOLLOWING SECTIONS BELOW DEAL WITH LINE VOLTAGE. LINE VOLTAGE CAN INJURE OR KILL. IF YOU ARE UNCOMFORTABLE WORKING AROUND LINE VOLTAGE, CALL A PROFESSIONAL REPAIR PERSON TO PERFORM THESE REPAIRS.
First of all, most System 3 games with a power module have an interlock switch located just inside the coin door. Of the two switches located on the right side of the coin door, the interlock switch is the lower, vertically positioned switch. It is called an interlock switch, because it will be closed when fully depressed, or when the switch "button" is fully extended and "locked". The benefit of an interlock switch is to apply power to a game when the coin door is open. To fully extend the interlock switch button, grasp it, and pull outward. It is not very common for these switches to fail. The more common issue is when the coin door is not fully seated against its frame, or the interlock switch bracket is bent inward. To effectively close and interlock switch, a coin door lock has to typically be installed. Without a door lock, it is possible for the coin door to become ajar or swing open, and the interlock switch will no longer be fully engaged. Having a coin door lock is a good idea in general, as it is cheap insurance to keep curious children and pets from touching parts inside the game. After all, there is 120v line voltage looming right around the corner inside the door.
If the interlock switch is suspected, the switch can easily be tested by performing a continuity test with an ohmmeter. When conducting a continuity test on the switch, first unplug the game from the wall outlet. Then, test the switch in both the depressed and extended positions. If the interlock switch does not allow power to pass through to the rest of the game in either the depressed or extended positions, replace it.
The interlock switch connects to the power module at connection A12P6. Although, in some instances, games with a power module may not have interlock switch. Instead, a jumper plug is installed at A12P6, bypassing the need for a switch.
Secondly, the F1 line voltage fuse may been blown. This is not too common, unless there is a catastrophic short in the game's power train, but some times fuses die from fatigue. The more likely suspect is F1's fuse holder. If pushing down on the top of the fuse holder, (the interlock switch must be extended outward while doing this), causes the game to power up, (even for a split second), the fuse holder has failed. These fuse holders are not the best quality, and it is common for them to fail. On the plus side, the power module can easily be removed from the game to change out the fuse holder. Here is a link to the spec. sheet for the EL-78 (HTB-64I) fuse holder and cap. See the brief section below for removal.
Finally, the F2 primary fuse may be blown. The failure of this fuse is as equally uncommon as F1, but it too can die from fatigue. Once again, the fuse holder is more than likely the failure point. The easiest way to determine if the F2 fuse holder is bad is to power on the game, extend the interlock switch outward, and check for line voltage at the bill validator outlet located closest to the cabinet wall. If voltage is not present at this outlet, but pressing the top of F2's fuse holder changes the outlet's reading from 0V to anything else, the fuse holder has failed. Follow the procedure below for removal of the power module to access and replace the F2 fuse holder. Here is a link to the spec. sheet for the EL-78 (HTB-64I) fuse holder and cap.
Power Module Removal
Unplug the game from the wall outlet, and remove the two connections at A12J6 and A12J6 of the power module. Then, unscrew the top ground connection, and the 4 screws around the corners of the power module. The power module can now be removed, and the fuse holder replaced. Reverse the previous steps for installation.
5.4.2 Low Voltage
5.4.2.1 +5VDC Logic Voltage
Logic voltage issues start with the +5vdc power supply. A simple fix is to replace the 500 ohm 1 watt pot used to adjust the +5vdc. The original factory pot was a not a sealed pot. Dirt, dust and contaminants can get into the pot and foul it. The result is either dead spots on the pot, or total failure.
5.5 Power Jumpers
Power selection (i.e. 100V, 115V, 120V, etc) is accomplished on Gottlieb System 3 games via a plug on the transformer assembly located in the cabinet bottom. Gottlieb supplied a plug for all common voltages enabling use in US, non-US, and low voltage locations. The picture in the gallery below on the right shows the orange 120V jumper plug installed.
- Gottlieb System 3 Voltage Selection
System 3 Tranformer Assembly with Power Jumper Highlighted. 
Typical Power Jumper Bag Stapled to Side of System 3 Cabinet. 
A 120V orange power selection jumper installed. A red jumper is used for 115V.
5.6 MPU Troubleshooting
5.6.1 Connecting a logic probe to the MPU
The best location for connecting a logic probe to the System 3 boardset is at capacitor C19, which located at the top of the CPU board. The positive lead (red) of the probe should be connected to the left/positive side of the axial cap, while the negative lead (black) should be connected to the right/negative side.
5.6.2 Using a Power Supply For Bench Testing
This MPU will not give diagnostic information by itself. A test ROM and diagnostic LED will be required to do this, such as Marco's test ROM from MarAlb on Pinside.
When using Marco's test ROM, disable the watchdog circuit by jumpering the lower portion of R29 to the negative/ground side of capacitor C19. This is a pull up resistor connected to one of the NAND inputs on U16. The "/ Watchdog Inhibit" is active when this is jumpered to ground. Note that jumpering the 5v side of the resistor may blow a fuse and cause damage to components, such as U16.
A diagnostic LED will also be required. Use a 5mm LED, and connect a 1k 1/4W resistor to the anode/positive side of the LED. Connect the other end of the resistor to the positive side of C19. Connect the cathode/negative side of the LED to the U1 CPU chip on pin 17 (address line A8).
To power the board, use the MPU's connector P1, and connect +5v to pin 1 and ground to pin 6. Or, connect +5v to C19's positive side, and ground to C19's negative side.
5.7 MPU boot issues
A very common issue with the System 3 platform is a message displayed on the DMD upon turning the power on. It can be common to see a "Check U3 or U6 error" upon attempted booting of the CPU. In most cases, this message is essentially telling the user that the lithium battery on the CPU board has failed.
5.7.1 Relocating the battery from the MPU board
The System 3 platform is one of the rare occasions where it is perhaps acceptable to leave the battery on the CPU board. This is due to the really low occurrence of the on-board lithium battery leaking. But, if the battery does leak, the reset IC is very close and may be damaged. System 3 PCB traces are very small and require jumpers to repair.
Should you choose to replace the battery, a good method is to cut the existing battery off the CPU board, and solder a lithium battery holder in its place as shown in the picture at right. After the battery holder is in place, a common replacement "button" type lithium battery can be used, like a CR2032 or CR2430.
If a remote battery pack is chosen as back up power for the non-volatile ram, use two AA batteries versus the typical three battery set up used with nearly every other platform. A blocking diode is not necessary when a remote battery pack with alkaline batteries is used.
Keep in mind that the System 3 CPU board's memory can be a little finicky, and in some instances a remote battery pack will not retain the memory.
Although rare, it is possible for a lithium battery to begin leaking and corrode the MPU board. In the picture at left, the CR2430 OEM battery has breached it's seal and begun to leak. This one was removed before it caused serious damage to the MPU board. Unfortunately, the IC just south of this battery is the obsolete and hard to find DS1210 power control IC.
5.7.2 NVRAM Installation
A nice alternative to a battery is non-volatile RAM (NVRAM). Pinitech can provide a suitable module which requires desoldering the DS1210 and the 6264 (or 6116 in some cases) and adding two jumpers as can be seen in the image at left.
5.7.3 System 3 Low Battery Boot Message
A low battery, missing battery, or battery not making good contact will cause the message shown in the picture at left when the game boots. While it might be tempting to investigate U3 or U6, make sure the battery is working properly before doing so.
5.7.4 Blank Display and Beeping
When the game is turned on, if the DMD is blank and the game just beeps loudly, turn off the game, check the U2 ROM chip on the MPU, and re-seat it.
Sometimes when replacing the battery, this chip gets knocked out of place.
5.7.5 Beeping and Garbled DMD
On power up, if a game gets stuck repeatedly beeping loudly and simultaneously blinking the DMD with jumbled/garbled characters, this is a problem on the MPU.
To verify that it is this issue, adjust the 5v about 0.03v up and down, and the game should then boot normally.
There are usually two possible causes for this issue:
- A bad U11 74HC123 chip. Note that this chip cannot be replaced with the HCT or LS variants, and must be the HC variant.
- This can be a timing issue with the watchdog timing circuit and the 5v not settling within the expected time period. Sometimes C20 and C21 capacitors go out of spec and affect this timing. Replace both capacitors (1uF 50v 20% axial ceramic capacitors).
Gottlieb was aware of this issue, so some games, such as Stargate, had a ROM revision to correct for this issue. For Stargate specifically, GPRPOM revision 4 corrects the issue.
5.7.6 Other Boot Issues - Stuck Address/Data Lines
If the game will not boot due to a fault with the MPU, use a logic probe and check each address line and data line on the U1 CPU chip. If any lines are stuck high, check to see what other chips also share that same line and replace them. A faulty chip can sometimes set an address or data line to high, which may prevent the board from booting.
If the chips that share the stuck line(s) have all been replaced, then consider replacing the VIA chips and/or CPU chip.
5.8 Game resets
5.9 Solenoid problems
5.9.1 Intelligent Solenoid Protection
Gottlieb System 3 games incorporate protection from stuck switches for solenoids. If a slingshot switch, for instance, closes 10 consecutive times without another switch closure occurring, the game will stop pulsing the slingshot coil for the duration of the game. Once a new game is started, the game will clear the "soft fault" and begin pulsing the slingshot coil when the slingshot switch closes.
This software logic is designed to protect a game with maladjusted switches from burning out a coil. If a slingshot switch were to be gapped too close, the slingshot coil may begin to "machine gun", quickly overheating the coil and potentially shorting the associated FET.
5.9.2 The Bottom Connectors on the Driver Board
Problems can occur if the game being worked on has had its playfield or head removed for transport or other reasons. Make certain that the two bottom outside connectors on the driver board are attached to the the proper locations. These connectors are used for the MOSFETs on the driver board to drive the solenoids, relays, and flash lamp circuits. Connectors A3J5 and A3J6 are both 18 pin connectors. If the identifying label on these connectors has been removed or fallen off (this is fairly common on System 3 games), A3J5 and A3J6 can be swapped. The end result will be coils and flashers which potentially lock on or engage when they should not.
5.9.3 Flasher Problems
If all flashers are out, and the associated fuse is good, measure resistance across this resistor as they seem to fail fairly often.
The image at left is from a Frank Thomas Big Hurt
5.9.4 Coil Problems
There can usually be a few causes for why a coil does not fire.
- Bad transistor on the driver board.
- Bad solder joint on the coil lug or a missing wire entirely.
- Bad diode on the coil.
- Be sure to check that the plunger moves smoothly through the coil--a swollen coil may prevent a plunger from moving. If this is the case, the coil will need to be replaced.
- Bad driver chips for the coil transistor(s).
- Bad ground connection on the transformer's PCB. To fix a ground issue, remove the PCB and check for cracked solder joints, and re-solder as necessary. It might also be a good idea to solder all those connections together on the PCB to help avoid future failures. Or, simply remove the PCB, cut off the connectors, use 4 large ring terminal connectors (for each group of grounds), and screw them to the transformer using the screws that held the PCB.
5.9.5 Motor Problems
Several Gottlieb System 3 games used at least one motor to implement playfield features...
- Frank Thomas Big Hurt - Glove motor
- Stargate - Glidercraft motor (uses one to make go side to side and a second one to move forward / backward)
- Cue Ball Wizard - Pool cue aiming motor
- Lights Camera Action - Rotating mini-playfield
- Gladiators - Moving ramp and shaker motor
- Tee'd Off - Gopher topper and under playfield roulette
- Waterworld - Deez ship
- Barb Wire - Big Fatso
- Operation: Thunder - Power plant spinning disc
- Rescue 911 - Ball lift for helicopter, helicopter blade, and helicopter rotation
- Wipeout - Ball conveyor belt
- Freddy: A Nightmare on Elm Street - Boiler door
- Shaq Attaq - Spinning disc
- Street Fighter II - Spinning flipper
- Super Mario Bros. - Spinning castle
- Mario Andretti - Spinning car unit
Motor issues are pretty straightforward. Either the motor is not getting power, the set screw used to secure the assembly to the shaft is missing or loose, the motor winding has a short or break in it, or the motor gearbox is binding, has stripped gears, or has become seized.
Nearly any motor used in a System 3 game is activated by a relay. Make certain that the controlling relay is engaging. If it is, make certain that the switch contacts on the relay are not pitted or fouled.
5.10 Lamp problems
5.10.1 Lamps Burn Out Quickly
If your game is burning up lots of lamps quickly, check your voltage setting underneath the playfield. A setting of 110v can cause bulbs to burn out too quickly, 120v fixes the issue.
5.10.2 No CPU Controlled Lamps or Switch Matrix
If there is General Illumination (GI), flashers, a working test switch, motors (at boot) and solenoids (at boot, such as the drop targets), but no CPU controlled lamps or switches in the switch matrix (including the flipper switches in test mode), then the ribbon cable between the driver board and the MPU may be bad.
The reason for this is that both the lamp matrix and switch matrix share strobes, which originate from the driver board, and are communicated over the ribbon cable to the MPU.
It can be replaced with a generic 20-pin 4" ribbon cable, like found on GreatPlainsElectronics
5.11 Switch problems
5.11.1 Conventional (Leaf and Microswitch) Switch Problems
5.11.2 Smart Switch Problems
The only approach to repairing a Smart Switch is to reflow the solder joints where the connector is soldered to the circuit board. These connections sometimes end up with either cold or cracked solder joints. Unfortunately, Smart Switches are not adjustable, nor do they have component level replaceable parts. If a Smart Switch is acting flaky or has failed, and reflowing the solder on its connector does not fix it, replacement is the only resolution. Smart Switches can be replaced with the same Smart Switch, (if available), or a standard leaf switch or microswitch would also be viable replacements.
5.11.3 Optical Switch Problems
If the associated LED on the opto controller board lights up when the light beam of an optic switch pair is broken, the switch pair is functioning properly. However, if the associated LED on the opto controller board stays on, and a ball is not located at the optic switch pair, there is something wrong with the optic pair. Typically, something is either blocking the light beam, or the receiver or transmitter needs to be cleaned. To clean either the receiver or transmitter optos, use a Q-Tip dipped in Windex to remove dust and dirt. Of course if the LED does not light up at all, there is something wrong with the optic pair.
5.11.3.1 Testing
- Testing the transmitter is quite simple. An item which is readily available, a digital camera, can be used. Just aim the camera at the transmitter opto, and look at the opto through the camera's screen. If the opto is on, it will appear as if it is lit up with a purplish-pink hue. The transmitter has a < 20 degree angle, so make sure your viewing it from close to 90 degrees. This method may lead to false negatives, depending on your camera.
- To test the opto receiver, an incandescent flashlight can be used. An LED flashlight may or may not work, and is not as effective for this test. Put the game in switch test mode, and aim the flashlight directly at the opto receiver. If the switch shows as closed in switch test, and / or the associated LED on the opto controller board lights, the receiver portion of the optic pair is functioning properly.
- Using a logic probe. Connect a logic probe to your machine (I used the recommended location on the main board.) Begin by probing either pin of the transmitter. You should see pulses on one of the pins. Now check the receiver. If the transmitter is working when it's pointed at the receiver, you should see pulses on one of the receiver pins. If there is a break in the beam there will be no pulses. You can use a known good transmitter from an adjacent opto and point it at your receiver to see this work and verify that your receiver is ok.
Should either the transmitter or receiver fail, replacement components are still readily available. Both components can be purchased from GPE. Here are links for the transmitter(QED123) and receiver (QSD124).
Opto Board LED "flat side" orientation
The picture at left, taken of an opto assembly from Gottlieb's Frank Thomas' Big Hurt, shows the orientation of the "flat side" of the opto transmitter/receiver pair. These boards are numbered MA-1331 (transmitter) and MA-1330 (receiver). This version of the board was marked with TX and RX on the backside silkscreen. These boards were replaced in later games by part numbers 31240 (TX) and 31241 (RX). They use Gottlieb opto part numbers XO993 (TX) and XO994 (RX). As noted above, part numbers QED123 and QSD124 work fine as replacements.
5.11.4 Opto Controller Board Issues
Opto sensing problems can also be caused by the opto controller board. If at all possible, swap the connectors of the opto pairs from a known working opto controller board to the possibly questionable opto controller board. Or simply swap opto controller boards. Games like "Big Hurt" which contain two Quad Opto Boards make this easy.
One common issue with these boards is the large high current resistors break loose from the board due to living in a high vibration environment.
5.11.5 No Switch Matrix or CPU Controlled Lamps
See the No CPU Controlled Lamps or Switch Matrix section.
5.12 Display problems
5.12.1 Alphanumeric Displays
Gottlieb games from Lights Camera Action to Operation: Thunder and Caribbean Cruise used the dual 20 alpha-numeric character displays that first appeared in System 80B games. These Futaba displays were quite hardy and rarely fail.
They do rectify AC voltage for use on the display via a gang of 4 diodes. These diodes can be tested via the normal procedure. you should also ensure that the PCB traces are intact.
5.12.2 Dot Matrix Displays
5.12.2.1 Failed U8G PAL
A consequence of removing or connecting DMD controller power with the game powered on is that the U8G PAL may fail. If this PAL fails, the DMD controller may not boot (the LED will not blink) or it may send garbage to the display. If you are having display problems and you've verified correct power (see below), there is a good chance that U8G has failed.
This part is available from The Pinball Resource.
5.12.2.2 Power Issues
If the DMD is not lighting up at all upon power up the game, the first order of business is to check all of the power sources needed for the display to properly function. Also, make certain that the power connection, A4J1, is properly seated on the back of the display. Please take note to only connect and / or remove connector A4J1 with the power off. Removing or connecting A4J1 with the power on can damage components on the display controller board.
As mentioned above, the DMD uses five distinct voltages for the display to function. The voltages necessary are:
- +5VDC
- +12VDC
- +62VDC
- -100VDC
- -112VDC
If the on board LED on the display controller board is flashing at an even rate, the +5VDC is good at the controller board. This does not necessarily mean there is +5VDC at the display, but it's a good indicator there is. If the controlled lamps are lighting up in attract mode, the +12VDC is typically good. Once again, having the controlled lamps functioning does not necessarily mean the power is successfully passing through the display controller board, but it too is a good indicator that there is.
CAUTION!!! THE FOLLOWING SECTION BELOW DEALS WITH HIGH VOLTAGES. HIGH VOLTAGES CAN INJURE OR KILL. IF YOU ARE UNCOMFORTABLE WORKING AROUND HIGH VOLTAGE, CALL A PROFESSIONAL REPAIR PERSON TO PERFORM THESE REPAIRS.
The best approach is to test the power at the display itself. All of the display power is fed by the A4J1 connection. To test the power at this connection, first connect the black lead of the DMM to a known good ground. The bottom left side of the foil panel in the backbox, where two green-yellow wires attach is a great source for the ground. Use a short alligator test lead to connect the black lead to ground. Once ground is connected to the black lead of the DMM, set the DMM for DC voltage. Use the method of only using one hand when probing these voltages. Place your free arm behind your back, and take precautions not to lean against the game's metal siderails, as they are grounded. With the DMM's red lead, touch each of the exposed pins at connector A4J1. The following voltages should be seen at A4J1:
- Pin 1 = -112VDC
- Pin 2 = -110VDC
- Pin 3 = 0V (Key)
- Pin 4 = 0V (HV Ground)
- Pin 5 = 0V (Logic Ground)
- Pin 6 = +5VDC
- Pin 7 = +12VDC
- Pin 8 = +62VDC
Note: you will likely have to use pin 4 (HV Ground) for black lead when verifying HV with Red lead on pins 1, 2, and 8. Pin 5 (logic gnd) is used for the black lead when testing LV pin 6, 7.
If the +12VDC is missing, check for this voltage on the display controller board. +12VDC should be present on the banded side of zener diode VR5. If +12VDC is not present here, test for +20VDC on the non-banded side of the D9 diode on the controller board. If +20VDC is not present, check fuse F6 on the transformer panel.
If the +62VDC is missing, check fuse F4 located on the transformer panel. If fuse F4 is good, make certain resistor R16 is not burnt on the display controller. If resistor R16 is burnt, rebuild the HV section of the display controller. Convenient rebuild kits for the HV section are available from Great Plains Electronics.
If either the -100VDC or -112VDC is missing, suspect fuse F3 located on the transformer panel. If fuse F3 is good, the fuse holder may be bad. Just like the fuse holders used for the line fuse and service outlet in System 3 games, the F3 fuse holder is susceptible to failure. In fact, it is pretty common for this fuse holder to fail. If pushing down on the top of the fuse holder, causes the display to light up, (even for a split second), the fuse holder has failed. Here is a link to the spec. sheet for the EL-78 (HTB-64I) fuse holder and cap. If the F3 fuse and fuse holder are both good, rebuild the HV section of the display controller. Again, a convenient rebuild kit for the HV section is available from Great Plains Electronics.
If all of the high voltages, +62VDC, -110VDC, and -112VDC, are not present, make certain there is continuity between pin 4 of A4J1 and ground. To test for this, turn the game off, and perform a continuity test between pin 4 and a known good ground connection. Again, the bottom left side of the foil panel in the backbox, where two green-yellow wires attach is typically a great source for ground.
5.12.2.3 DMD Freezes After Entering Attract Mode
If the graphics on the DMD freeze after entering attract mode, this may point to a failure with the 6264 Static RAM at U4 and/or the 74HCT08 chip at U6.
5.13 Sound Problems
5.13.1 Sound Board Troubleshooting
Sound failures in a System 3 machine are usually manifested as a complete lack of sound and a locked-on/off LED on the sound board. In the vast majority of instances, this is due to a failure of one of the 6116 SRAMs - typically H3 - on the sound board. However, it is ill-advised to simply shotgun this component because of how it is normally soldered to the board and the fine traces on the board that can be easily damaged without the proper equipment and experience to replace it. It is also possible that the problem lies elsewhere so changing out the 6116 without doing some basic troubleshooting may not solve your problem anyway. By following the steps below, you can easily diagnose and repair most System 3 sound problems. In a brief summary: check for voltages, a reset signal, the clock signal, valid ROMs, potentially bad RAM, and any locked-on data/address lines.
5.13.1.1 MA-886 Troubleshooting
The base MA-886 sound board used in Nudge-It is fully stuffed with two AY-3-8913 sound chips. The procedure to test and troubleshoot this board is outlined in the System 80 section of Pinwiki here.
5.13.1.2 MA-886-XXX and MA-1629
Because these boards do not contain the AY-3-8913 sound chips but instead rely on some type of aux sound board, these boards are simpler to diagnose and test.
5.13.1.3 Voltages
For the sound board to work properly, like every other logic board, it needs power. The sound board requires +5, +12 and -12 VDC to operate correctly. However, for the logic section to operate properly, the only voltage that is needed is +5v. If the LED on the sound board does not come on at all (it is powered by the 5v line), then you may not have +5v going to the sound board. The best way to check the voltages at the sound board is to measure across the bypass capacitors on the power input lines: C18 for +5v, C10 for +12v and C19 for -12v. If you are missing one of these voltages, especially the 5v, you may have a problem with connectors, the wiring harness or one of the power supplies. The 5v is fed from the A2 power supply board; the +12v and -12v come from the A5 auxiliary power supply board. Once you have verified voltages you can move to the next step.
5.13.1.4 Reset
The sound board contains two complete computers (6502, RAM and ROM) that must work together to generate sounds. However, the one thing the sound board lacks is a way to reset itself on power-up. The signal to do this comes from the main CPU board through the P1 connector on the sound board. When the machine is first powered on, and when the CPU is ready, it sends a Master Reset signal to the sound board which is why you normally hear a high-pitched squeal from the machine. If the board does not receive this signal, and the voltages at the sound board are good, the LED will likely be locked on. However, there is a provision for you to manually reset the sound board by pressing the SW2 button on the sound board. If you press this button, get a squeal and the LED starts flashing, then you have a problem with the reset line coming from the CPU. This could be pins, connector, harness or a problem on the CPU board itself. If this happens, move on to Signal Lines below. If after pressing the reset button the board is still locked up, this *could* indicate a bad 74HC08 at G5 which can happen if the board has suffered catastrophic damage like plugging the wrong connectors into the wrong places. It could also mean the board is locked up hard and is not responding to the reset signal. If so move on to ROMs below.
5.13.1.4.1 Signal Lines
If the sound board is booted, either by the CPU board or the reset button on the sound board, then the next thing to check are the signal lines by putting the machine into sound test. The sound test confirms basic connectivity between the CPU and sound boards. There are 8 signal lines that are tested between the CPU and sound boards, Combinations of these lines are triggered to send commands to the sound board. When a combination of lines are triggered they are loaded into the 74LS374 latch at A3 and the outputs are tied to the data bus. A failure of the latch can manifest itself as one or more of the data lines not working in the sound test, or the board could be locked up because the latch has suffered a catastrophic failure shorting the data bus to ground. Not triggering some of the lines could also be a connector or wiring harness problem (which can also cause a problem with the reset line) as well as a failure of the VIA that controls the sound board which is located at U5 on the CPU board. If all the signal lines test correctly but the sound board only starts by pressing the reset button on the sound board, then there’s either a problem at G5 on the sound board or the master reset is not being received from the CPU board. Check the harness connection between the CPU and sound board. If that tests ok, then there is a problem on the CPU board that needs further investigation.
5.13.1.4.2 ROMs
There are two sound ROMs on the board, the DROM at K2 and the YROM at K3. Either pulling these ROMs and verifying them with a ROM burner or replacing them with known good ROMs is the next logical step. Since these are EPROMs, it’s possible for the contents to suffer “bit rot” and no longer be valid. Truth be told, the failure of one or both of the ROMs is highly unlikely. However, since these components are socketed, it’s easy and relatively cheap to swap them out and hope it solves the problem. While you might want to console yourself with the idea that swapping the ROMs insures you have the most up-to-date ROMs installed, in reality, Gottlieb almost never updated the sound ROMs once they were released into the wild. Chances are what came with your machine is likely the only version of the sound ROMs available for it.
5.13.1.5 Test ROM
If you’ve come this far and the board still isn’t working, the best advice is to get the sound board test ROM from Marco Albus. This test ROM, the function of which can be seen in this video: https://youtu.be/gutAv5x9Xsc will allow you to pinpoint the problem with the board, whether it be one of the RAMs, CPU, interrupt generator or one of the input latches.
5.13.1.6 No Test ROM
If you’re here, you really need to think about either going back to getting the test ROM or finding someone that has the tools and experience to fix this board. These boards are hard to come by and you do not want to damage a board shotgunning components in the hope you can fix it. However, if you are bound and determined to shotgun this board in an attempt to fix it and you’ve already gone through the previous steps, now is the time to replace H3 on the sound board.
*NOTE* The SRAMs on the sound board are speed sensitive! The schematics specifically call out that the 6116s should be at least 150ns or faster. If you install SRAMs that are slower than 150ns, the board may or may not work.
If this still doesn’t solve the problem then the next components to swap in order until the board works are:
6116 @ H2 (remember 150ns or faster)
If pressing the reset button gets the board to work, then 74HC08 at G5 then 74LS374 at A3 (if not done already)
If pressing the reset button doesn’t get the board to work, then 74LS374 at A3 then 74HC08 at G5 (if not done already)
6502 @ T3
6502 @ N1
While the vast majority of failures will be fixed by replacing the H3 SRAM, following the above procedure will insure you catch any other potential problems and minimize the possibility for unnecessary work and board damage.
5.14 Flipper Problems
Since the System 3 flippers are not solid state controlled, the procedure for troubleshooting a failing flipper is essentially the same process as all previous Gottlieb® platforms.
5.14.1 Flipper Not Functioning
When flippers are not functioning at all, the first determination which has to made is whether the problem is mechanical or electrical in nature.
5.14.2 Flipper Loss of Power
Likewise, flippers can become weak due to mechanical or electrical issues. The most common sources for weak flippers are due to either pitted / fouled EOS or flipper button cabinet switches. Both of these switch styles can be burnished with an ignition file to dress the switch contact faces. If switches are severely pitted, replacement is recommended.
As for mechanical issues, it is common for System 3 flippers to crack or break their associated flipper bushing. Replacement of broken flipper bushings is recommended.
Flipper flutter--Check the EOS switch to verify that the wires don't have a cold solder joint issue.
5.14.3 Flipper Sensor Board
If a flipper sensor board fails or malfunctions, the flippers will not be disabled. However, making selections in game test mode, bookkeeping, changing game adjustments, entering high score initials at the end of the game, and choosing selections during game play via the flippers will not be possible.
The components used on the sensor board are minimal. If a sensor board is suspected as the core of an issue, removing the board and testing the components on the board is recommended. Equally, bad grounds could be the source of why the sensor board is not properly working. Components on the sensor board need a logic ground to function properly. Make certain the ground on the board has continuity between it and the transformer panel's metal case located in the bottom of the cabinet. Pins 5 and 8 of the U1 (MCT6) optocoupler on the sensor board are the ground reference.
5.15 Drop Target Problems
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5.16 Vari-Target Problems
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6 Game Specific Problems and Fixes
6.1 Shaq Attack
Score Board Displays - Sometimes, the digits on the score board do not light, which can be caused by a bad transistor and/or a failed display digit. A close replacement to the display digit with an identical pin-out is a Lite-On LTS-546AHR, found on mouser and Digikey. Note that the digit is slightly smaller than the original. There is a short tutorial on Pinside.
6.2 Stargate
Stargate Rope Light - If the rope light, used exclusively on the game Stargate, is not lighting, do not immediately suspect that the rope light or its drive transistor (Q22) has failed. On the backside of the backbox lamp insert, there are 3 3.3 ohm 7 watt resistors in series between the +20VDC flash lamp power and the rope light. The purpose for these resistors is to reduce the amount of power used to illuminate the 18 lamps used in the rope light. Over time, these resistors can become hot, and either burn, desolder themselves, or break away from the eyelets where they are soldered. Likewise, the wiring used to tie the resistors in series can become brittle or burn. Make certain the resistor circuit is intact before troubleshooting an unlit rope light.
Note: The physically smaller resistor on the far left in the pic (circled along with the other 3 resistors) is a 0.33 ohm 5 watt resistor used for the 4 flashers located on the backbox lamp inserts. This resistor is not part of the rope light circuit, and probably does not need replaced.
Annoying "Shoot the Pyramid" Call-Out - After starting a game and when the ball is sitting in the shooter lane, press and hold both flipper buttons for 3 seconds. The frequency of call-out should be greatly reduced for the rest of the game. Additionally, there is a modified sound ROM available which has the call-out removed entirely.
6.3 Rescue 911
Rescue 911 Beacon Lamp Not Rotating - If the motor is spinning, but the reflector isn't rotating, you may need a new rubber on the reflector's rotating plate. If there is melted black residue all over the inside of the beacon, be sure to clean it all up first. PBResource has the new rubber as part # 31257.
Rescue 911 Missing Beacon Lamp - If the beacon lamp topper is missing from the game or is unreparable, it can be replaced with a Peterson 771R or Wolo 3110-R. These are off-the-shelf items that can be found on amazon.com or certain auto parts stores. These beacon lamps have 12v car adapter plugs, which will need to be cut off and modified to use a 2-pin female molex Mini-Fit Jr 4.2mm connector plug to fit the connector found in the backbox.
Wolo 3110-R
Peterson 771R
Beacon Measurements
Rescue 911 Helicopter Arm Does Not Move - If the motor that drives the helicopter arm runs, but the arm does not move, check under the playfield where the shaft from the motor meets the shaft going up to the helicopter arm. Each end has a thimble-shaped gear (called a "collar"), which should be mated together with a plastic barrel (called a "neoprene sleeve"). The original neoprene sleeve was black and brittle due to age, and is prone to shatter when stressed. PBResource has a replacement as part # 30558.
Rescue 911 Helicopter magnet and/or spinning blade doesn't work - When either the magnet or the motor that spins the helicopter blade doesn't work, that usually indicates that there is a problem with the wiring. The wiring gets stressed and often breaks somewhere in the insulation because of the repeated movements of the helicopter arm. Simply replace each wire with 22 gauge stranded wire. Use a mini-fit jr. pin extraction tool and mini-fit jr pins for the end with the connector. If you have to replace one wire, it's best to replace them all at the same time.
Rescue 911 Helicopter Arm wiring gets caught on post caps - If the wiring for the helicopter that feeds down the length of the arm gets caught on the post caps of plastics, make sure that all those posts have acorn post speed nuts, rather than any thing else. These post caps allow the wire to slide over them easily without getting hung up. Other post caps will interfere and cause the wiring to get snagged.
Rescue 911 Helicopter doesn't rotate correctly - When the arm of the helicopter swings around, there is a friction wheel at the end of the arm that presses against the round plate. If there is enough friction and pressure, that wheel rolls and causes the helicopter to rotate on the end of the arm. Unfortunately, this mechanism, while clever, tends to be problematic. There are a few things that can be done to help address this:
- Replace the friction wheel (Part # 30365 from PBResource). Often times, it develops a flat, worn spot and won't turn any more.
- Make sure the screw on the friction wheel is tight.
- Make sure the screw in the center of the friction plate (and plastic) is tight (note that the plastic will spin loosely. The screw actually only tightens down on the helicopter arm).
- Make sure that the miter gears under the helicopter are turning and aren't skipping over teeth.
- Sand the new friction wheel with 180 grit sandpaper just enough so there is no shiny or smooth surface on it.
- Replace the three compression springs under the friction place (Part # 30372 from PBResource).
- As a last resort, stick a 1/2" grommet under the left side of the friction plate to help push it up slightly so it presses against the friction wheel when it moves over that area on the friction plate.
- If the helicopter still isn't quite aligning properly with the ball lift, the bracket with the "heli lower stop" opto switch may need to be bent forward or back slightly to either let the arm travel further or less far. Note that bending it too far may cause the helicopter arm to make contact with and damage the plastic buildings.
7 Repair Logs
Strikes N' Spares
- Problem: Left plunger gate (solenoid 3) overheats, burning the coil and melting plunger tip.
- Cause: The upkicker (solenoid 5) plunger is sticking up, blocking upkicker opto.
- Solution: Replace upkicker plunger (30463), spring (26739) coil mounting bracket (15409) and left plunger gate parts as necessary.
Teed Off.
- Problem: Gopher spin wheel hardly moves at all to throw the ball. Spin relay "B" attached to the underside of the playfield has good, clean contacts.
- Cause: The "B" (gopher wheel spin) relay does not stay energized long enough to turn the spin motor on for a sufficient amount of time.
- Solution: Connect a 2200uf/50V electrolytic capacitor across the "B" relay's coil. The positive (+) side of the capacitor will connect to the banded (cathode) side of the diode on the coil. This will make the relay coil stay energized for a longer period of time so the motor will spin longer.
Rescue 911
- Problem: Intermittent boot problems. Would not boot in about 1 out of every 5 tries. Nothing displayed on DMD. LED's on the MPU and DMD driver board would come on and stay solid (no flashing).
- Cause: The U11 chip was bad.
- Solution: Replaced the U11 chip.
Rescue 911
- Problem: In the setup the 1st replay level displayed as "150,??0,000". Memory tested good in RAM test.
- Cause: RAM was bad even though it was testing good.
- Solution: Replaced RAM chip.
Super Mario Bros.
- Problem: The launch button is inoperable in game, (button will not activate the shooter lane coil), but works in switch test.
- Cause: Shooter lane switch was not identified as closed (check in switch test with ball resting on switch). Switch was dirty
- Solution: Clean shooter lane switch with business card (check adjustment of switch too!).
7.1 Mixed-Up 6-pin Power Supply & Driver Board Connectors
It is possible to mix up the 6-pin connector on the 5V power supply and the 6-pin connector on the driver board. Doing so will send 21v to the ground plane.
In a Rescue 911, possible damage may include:
- Display Driver Board: 6264 Static RAM (U4), 74HCT08 (U6), U8G PAL (U8). Note: Replacing *only* the U8G chip without replacing the other failed chips first may damage the new U8G chip.
- Sound Board: 74HCT374 (A3), 74HC08 (G5), 2x 6116 Static RAM (H2 and H3).
- DMD: Large sections were fully lit or fully dark; replaced the DMD.
8 Parts Substitutions & Replacements
8.1 Playfield
8.1.1 Lamp Sockets
- #44/#47 1/2" Bracket Diode Board (#26622): Replacement from All Electronics