Gottlieb System 3
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1 Introduction
Put system info here
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-886-722 | MA-1294 | MA-1294 C12 is marked C12 & wire jumpers used | |||
| Vegas | 723 | MA-886-723 | MA-1294 | ||||
| Deadly Weapon | 724 | MA-886-723 | MA-1294 | MA-886-723 is not a typo | |||
| Title Fight | 726 | MA-886-726 | |||||
| Nudge-It | N102 | MA-886 | |||||
| Bell Ringer | N103 | ||||||
| Car Hop | 725 | ||||||
| Hoops | 727 | MA-1538 | MA-1294 | ||||
| Cactus Jack's | 729 | ||||||
| Class of 1812 | 730 | MA-1629 | MA-1604 | MA-1604 Uses OKI chip at U1 | |||
| Surf 'n Safari | 731 | MA-1629 | MA-1712 | MA-1712 Uses OKI chip at U1 | |||
| Caribbean Cruise | C102 | ||||||
| Operation Thunder | 732 | 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 | DMD | |||||
| Cue Ball Wizard | 734 | MA-1423 | MA-1629 | MA-1770 | DMD | ||
| Street Fighter II | 735 | MA-1629 | MA-1770 | DMD | |||
| Tee'd Off | 736 | MA-1629 | MA-1770 | DMD | |||
| Wipe Out | 738 | MA-1629 | MA-1770 | DMD | |||
| Gladiators | 737 | MA-1629 | MA-1770 | DMD | |||
| World Challenge Soccer | 741 | MA-1629 | MA-1770 | DMD | |||
| Rescue 911 | 740 | MA-1629 | MA-1770 | DMD | |||
| Freddy: a Nightmare on Elm Street | 744 | MA-1629 | MA-1770 | DMD | |||
| Shaq Attaq | 743 | MA-1629 | MA-1770 | DMD | |||
| Stargate | 742 | MA-1629 | MA-1770 | DMD | |||
| Frank Thomas' Big Hurt | 745 | DMD | Uses a different A17 diode board. 8 positions of 1N4148 diodes are replaced with 1N4008 diodes for # 86 lamps | ||||
| Waterworld | 746 | MA-1629 | MA-1770 | DMD | |||
| Strikes N Spares | N111 | None | MA-2112 | DMD | |||
| Mario Andretti | 747 | MA-1629 | MA-1770 | DMD | |||
| Barb Wire | 748 | MA-1629 | MA-1770 | DMD | |||
| Brooks & Dunn | 749 | None | None | None | None | Game never went into production |
3 Technical Info
3.1 The System 3 Board Set
Clicking the link above will direct to a new page showing all of the System 3 boards.
3.2 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-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
3.3 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.
3.4 Connector Designations
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).
3.5 Switch Matrix
The Gottlieb® System 3 switch matrix consists of a maximum of 108 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 any other manufacturer. The System 3 switch strobe lines and the lamp strobe lines are shared by the same lines. Due to this design, all switch strobes 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.
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 |
3.6 Lamp Matrix
Finally, Gottlieb® employed a lamp matrix starting with the System 3 platform. The System 3 lamp matrix consists of a maximum of 108 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 any other manufacturer. The System 3 lamp strobe lines and the switch strobe lines are shared by the same lines. All lamp 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.
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 |
3.7 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. Mini-Fit 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 primary functions of this board is used to power 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.
+++explain further++++
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 is:
- +62 VDC
- -100 VDC
- -112 VDC
3.8 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.
3.8.1 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 chip is installed at U3, jumper 3 must be installed and jumper 4 removed. If a 6264 chip is installed at U3, jumper 4 must be installed and jumper 4 removed.
3.9 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. 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.
3.10 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.
3.11 Sound Boards
3.12 Display Boards
3.12.1 Alphanumeric Displays
3.12.2 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:
- +5VDC
- +12VDC
- +62VDC
- -100VDC
- -112VDC
3.12.3 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:
- +62VDC
- -100VDC
- -112VDC
Although not really considered high voltage, +20VDC is regulated down to +12VDC on this board for the DMD.
3.13 Solenoids and Relays
stub
3.14 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.
3.14.1 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.
3.15 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.
3.16 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 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.
3.17 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 Problems and Solutions
4.1 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.
4.2 Connectors
4.3 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.
It should be noted that 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.
4.4 Power Problems
4.4.1 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.
4.4.2 Low Voltage
4.4.2.1 +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.
4.5 Power Jumpers
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4.6 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.
4.6.1 Relocating the battery from the MPU board
The System 3 platform is probably one of the rare occasions where is it not recommended to move the battery off the CPU board. The System 3 CPU board's memory can be a little finicky, and in some instances a remote battery pack will not work. The best method is to cut the existing battery off the CPU board, and solder a lithium battery holder in its place. After the battery holder is in place, a common replacement "button" type lithium battery can be used.
However, if a remote battery pack is chosen as the back up power for the non-volatile ram, use only two AA batteries instead of three. A blocking diode is not necessary to be placed in circuit with the remote battery pack.
4.6.2 Repairing Alkaline Corrosion
4.6.3 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 side of the axial cap, while the negative lead (black) should be connected to the right.
4.6.4 Using a PC Power Supply For Bench Testing
4.7 Game resets
4.8 Solenoid problems
4.8.1 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.
4.9 Lamp problems
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.
4.10 Switch problems
4.10.1 Conventional (Leaf and Microswitch) Switch Problems
4.10.2 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.
4.10.3 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.
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. 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.
In any of the above cases, there could be a problem instead with the opto controller board. If at all possible, swap the connectors of the optic pairs from a known working opto controller board to the possibly questionable opto controller board.
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.
4.11 Display problems
4.11.1 Alphanumeric Displays
4.11.2 Dot Matrix Displays
4.11.2.1 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
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.
4.12 Sound problems
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4.13 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.
4.13.1 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.
4.13.2 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.
4.13.3 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.
4.14 Pop bumper Problems
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4.15 Slingshot problems
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4.16 Drop Target Problems
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4.17 Vari-Target Problems
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5 Game Specific Problems and Fixes
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.
6 Repair Logs
Did you do a repair? Log it here as a possible solution for others.
Strikes N' Spares.
- Problem: Left plunger gate (sol 3)overheats, burning the coil and melting plunger tip.
- Cause: The upkicker(sol 5) plunger is sticking up, blocking upkicker opto.
- Solution: Replace upkicker plunger(30463), spring(26739) coil mounting brkt(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 2200 uf @ 50 volt 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.