EM Repair

Note: This page is a work in progress. Please help get it to a completed state by adding any useful information to it.

1 Introduction

Put system info here

2 Safety

Pinball machines operate off line voltage (120V in U.S.) so care must be taken when working on your machine. If you are not comfortable with the risk you should only attempt repairs that can be done with the machine unplugged.

Most EM machines operate on 6.3V and 25V AC which is safe. However, line voltage will be present from the line-in cord to the primary side of the transformer. Also, some machines have coils that operate on 120V so some relay switches and score motor switches have 120V present on them. Finally, some older machines have 120V going to the start switch. On these games you should check to make sure the fish paper insulation is still in good condition.

3 Games

The "Big Three" manufacturers were Gottlieb, Williams and Bally. The "best of the rest" would probably include: Chicago Coin and Midway as well as some foreign brands such as Recel, Playmatic and Rally. There were many companies that only produced a few games, especially early on.

A quick search of the Internet Pinball Database:

http://www.ipdb.org/search.pl?gtype=EM&searchtype=advanced

Shows that between all the manufacturers, there are over 3403 games within this very broad category.

4 Technical Info

4.1 Start-up Sequences

The following is the start-up sequence for a Gottlieb Southern Belle. The Southern Belle is a woodrail from 1955 with lightbox scoring. In other words, it has no score reels. Other Gottlieb woodrails from this era will be similar, but not exactly the same. You will need to consult your schematic and figure out the exact sequence if it differs slightly from the one below:

Southern Belle Start Sequence:

1. Push start button, pulls in start S relay

2. Start relay resets 100K unit, closing switch at -1 position on 100K unit

3. Closed switch at -1 position pulls in Z relay

4. Z relay pulls in ball release coil which is held on by 2 ball hole switches and a switch on the ball release unit

5. The balls move off the two switches, opening the two switches, so now the ball release coil is retained by Z only.

6. Switch on Z relay closes and allows pulsing of 10K unit through Motor 1A

7. 10 K unit continues to pulse until it hits position 9 or 19 or 29 on the 10K unit, then the "bridge" there, in series with the NO switch (which closes once/pulse) on the 10 K unit pulls in the M relay.

8. The M relay steps the 100K drive coil up and stays pulled in until the 100K NC switch is opened (upon stepping once)

9. The 100K step moves the 100K stepper off the -1 position, opening the switch on that keeps the Z relay pulled in.

10. The Z relay releases – the 10K unit can no longer be pulsed though the switch on the Z relay.

11. Z relay opening also releasing the ball release coil.

12. The N flip/flop switch seems somewhat redundant in this setup.

The following is the start-up sequence for a Gottlieb Roto Pool from 1958. You can see it is similar, but not exactly the same as the Southern Belle sequence.

Roto Pool Start Sequence:

1. Push start button, pulls in start S relay

2. Start relay resets 100K unit, through NC switch on motor 1C closing switch at -1 position on 100K unit

3. Closed switch at -1 position pulls in U relay

4. U relay pulls in ball release coil, which remains on by the U relay, a switch on the unit itself and a flip/flop on the N relay

5. Switch on the U relay is closed, allowing pulsing of the 10K unit though switch on motor 1A

6. 10 K unit continues to pulse until it hits position 9 or 19 or 29 on the 10K unit, then the "bridge" there, in series with the NO switch (which closes once/pulse) on the 10K unit pulls in the 0-9 coil relay

7. The M relay pulls in and is held in by it's own switch and a NC switch on the 10K unit and remains on until the 10K unit steps. The 100K step moves the 100K stepper off the -1 position, opening the switch on that keeps the U relay pulled in.

8. The U relay releases – the 10K unit can no longer be pulsed though the switch on the U relay.

9. The N flip/flop switch activates at some point, releasing the ball release coil (IMO, this is a poor design, leading to a burnt coil for any number of reasons (no FMEAs at Gottlieb?)

Gottlieb Start-up Sequences from the 1970s

There is a great repository of Gottlieb start-up sequences gleaned from numerous game manuals here:

http://www.xmission.com/~daina/tips/pub/emTips.html

70s Williams Start -Up Sequence (4 player)

1. When the start (credit) button is pressed, the credit unit is decremented. This is done through the CREDIT UNIT zero position switch and a set of parallel switches that ensure the game is in "game over" or still on player 1, ball 1, and not at the maximum number of players (COIN UNIT last position switch).
2. The end of stroke (EOS) switch on the CREDIT UNIT decrement coil energizes the COIN relay.
3. The COIN relay:
   • Trips the GAME OVER latch/trip relay once the PLAYER UNIT and BALL COUNT unit reach zero.
   • Energizes the RESET relay.
   • Runs the SCORE MOTOR.
4. The RESET relay:
   • Energizes the BALL COUNT unit reset through the SCORE MOTOR.
   • Energizes the GAME OVER relay latch coil.
   • Energizes the COIN UNIT reset coil.
   • Energizes the NO.1 and NO.2 (score) RESET relays, through the score motor.
   • Runs the SCORE MOTOR.
5. The score reset relays pulse and zero the score reels, through a switch on the score reel that opens in the zero position to stop the reset for that reel.
6. The SCORE MOTOR runs until all score reels and the BONUS UNIT reach the zero position.
7. The RESET relay decrements the BONUS UNIT until it reaches the zero position.
8. When the BONUS RELAY drops out it energizes the OUTHOLE relay through a different BONUS UNIT zero switch and through the SCORE MOTOR.
9. The OUTHOLE relay:
   • Runs the SCORE MOTOR and increments the BONUS UNIT once.
   • Energizes the BALL RELEASE coil which kicks the ball into the shooter lane.

Bally start sequence:

1. When the coin is inserted into the game the coin relay energizes. It stays energized through its own hold on switch and a score motor switch. Once the start button is pressed the credit relay is energized which in turn energizes the coin relay if there are sufficient credits.

2. The lock relay is then energized by the coin relay at which time the game illuminates. The lock relay stays energized through its own hold on switch and a delay relay switch.

3. The coin relay then energizes the reset relay through a switch on the game over relay.

4. As the score motor runs, it energizes any score reset relays. The score reset relay will now resets the score reels to zero.

5. The total play meter is advanced by the coin relay via the score motor.

6. The ball count and player units are then reset by the reset relay via the score motor.

7. The credit unit is stepped down by the coin relay via the score motor.

8. The game over relay latch coil is now energized by the coin relay via the score motor.

9. The 100,000 relay latch coil (if equipped) is energized by the coin relay via the score motor.

10. The ball is now introduced into the shooter lane by the outhole relay via the score motor (assuming the outhole switch is closed).

11. If multiple players are added by the start button, the coin relay advances the coin unit,advances the total play meter, and steps down the credit unit.

4.2 Schematics

A guide to reading schematics is available here: http://tuukan.fliput.net/emkytkis_en.html

5 Problems and Fixes

5.1 Lubrication

Over-lubrication causes far more trouble in coin operated equipment than under lubrication. Practically all cases of poor contact on switches and wiper disks are due to oil or grease, or oil vapor, which forms a film or residue on the contacts and will not allow current to pass through. Excess lubricant may also seep into clutches causing them to slip.

IMPORTANT: NEVER USE VASELINE FOR LUBRICATION OF ANY PART OF THE MACHINE! Vaseline is not a true lubricant. It leaves a dirty and gummy residue and becomes very thick when cold.

Step-up levers, ratchets, cams, shafts and other sliding or oscillating parts should be very lightly greased with special coin machine lubricant. The bakelite disks (biscuits) on the motor units and step-up units will require lubrication with the special coin machine lubricant only after the grease is completely evaporated or when the film of the grease becomes dirty (machines with bakelite disks only). In either event, clean the parts thoroughly with a solvent, then apply an extremely thin coat of the special grease.

Solenoid plungers should not have a lubricant of any kind. Should there be a sluggish tendency or if plungers are sticking, the parts should be cleaned with a solvent and flaked graphite if anything, applied on reassembly.

The general rule is "when in doubt, don't". There are very few places on a pinball machine that need lubrication and they're only in spots that have metal-to-metal contact. When needed, a good choice is "Super Lube Teflon Grease", a clear synthetic grease with Teflon. It can be found at local hardware stores or online, for example: http://www.pinrestore.com/Supplies.html

5.2 Switches

Before adjusting switches, make certain the screws holding the switch stacks are down tightly. Bakelite spacers in the switch stacks, due to excessive moisture, have occasionally shrunk by drying out, causing poor adjustment.

If you clean a set of points, and find yourself having to do it again soon. Check the rivet on the point blade. They can come loose and arc and prevent good contact with the blade. Easy to repeen it, or even solder it down. Clean it and you'll be good to go. LTG :)

5.6 Score Reels

There are many types of score reels. Score reels are essentially 10 unit steppers. In fact, many of the parts catalogs refer to them as such. Each manufacturer has their own individual design. Within each manufacturer, there may be several designs and even variations within each design. For instance Gottlieb introduced "rat trap" score reels around 1955 on multiplayer games (Duette) and around 1959 on the single player game Miss Annabelle. Around 1966, Gottlieb moved away from the rat trap score reels to a newer, less complex design, called a "decagon" unit. However, the decagon unit itself has several iterations, with 10 sided reels, round reels and plastic parts replacing metal parts. Around 1975, they did a major redesign of the decagon unit that is cheaper and considerably easier to service than prior versions, yet it is still called a "Decagon" unit.

The point of all this is that there are many designs and iterations of these designs and you will need to figure out your particular unit for yourself, as it is unlikely that every iteration will ever be covered in a step by step guide.

Score units generally provide the following functions:

1. Step once and only once per signal

2. Provide a signal used by the startup sequence that the score reel is at zero. The majority of the time the switch is closed at zero, but sometimes it is open, so check you schematic and other score reels in the machine if you are not sure.

3. Provide a signal that the score reel did move. This is often a switch that is normally closed (end of stroke switch) and opens when the plunger moves. This can be a cause of locked on coils, so you need to be sure it opens. Some people advocate keeping them permanently open on Gottlieb Decagon units, but I don't see a need for that.

4. A signal when the unit gets to nine, this is used to "carry over the decade" at the next score. Of course the highest score unit will not have one of these, since there is no higher score reel to carry the decade over to.

5. Provide a signal to the high score and match features of a game as to exactly where the score reel is. This is typically done via the circuit board on the reel and a wiper that runs across it.

Generally, you will need to do the following to service/rebuild one of these units, minimum is usually to clean the circuit board and score reels themselves and de-gunk the unit so it steps smartly. You can go deeper as required or desired either due to the necessity of the repair or your level of comfort taking it apart.

Pull the score unit from the game and let it hang.

• Remove the retention on the circuit board

• Pull the score reel

• Clean up any gunked up, sticky moving parts with Mean Green or a similar degreaser

• Clean up the score reel with Novus. BE CAREFUL, do not clean the numbers off the wheel.

• Degrease the circuit board

• Sand the face of the circuit board with 600 grit wet or dry sandpaper, using rubbing alcohol as the lubricant.

• Apply a Teflon based lubricant to the circuit board, like Superlube or a similar product.

• Clean all the contact points.

• Re-assemble and verify the unit steps correctly and the contacts open and close correctly

A Youtube Video of the process on a Gottlieb Decagon is here:

Teardown – (Note, I have since found out that it is a lot easier to do this if you de-solder the coils): http://www.youtube.com/watch?v=XVdUp5kVkjk

Cleanup http://www.youtube.com/user/newmantjn#p/u/13/QZVRilwjZZQ

Rebuild http://www.youtube.com/user/newmantjn#p/u/14/IMvvJCtBJc0

Epilogue - Fixing a problem: http://www.youtube.com/user/newmantjn#p/u/5/zQUHiT7BJB8

5.7 Drop Targets

Complete Teardown and Rebuild of a Gottlieb Drop Target Bank

This procedure was developed a few years ago while working on a Volley. The Volley has three, 5 target banks. Sometime after rebuilding the first one, I decided that there must be a better way. No way would David Gottlieb have put up with dental picks and the like on his assembly line. So my goal was to develop a procedure that would require only fingers, or maybe a little "help" from a screwdriver. Note that this is for a complete overhaul. You might have to adapt if you just want to change a target or two. Generally, I like completely overhauling something and not worrying about it again, ever.

One thing I have discovered over time is that a common mistake is to spend a lot of time trying to save a little time. This comes up in auto repair a lot. People will try real hard to not pull off a part which is held on by 4 bolts. So, in order to save the 3 minutes of time removing the 4 bolts, they will add an hour to the repair time trying to work around the part they should just have removed. The procedure really takes everything apart. It took about 45 minutes to completely disassemble the bank, clean every part and re-assemble. By contrast, the when I did a Big Brave bank a few years prior to this, it took me hours to get it done, since I tried to not take it apart all the way.

One more thing – you can leave some of the sub assemblies together if you don't plan on running the parts through a cleaner. For instance, you could leave the brackets attached to the back of the target bank. It's your machine, you decide how far you want to take it down.

Drop Target Bank Rebuild Procedure:

Remove Drop Target Bank from game

1. Put the playfield up in the full service position, with the playfield resting against the backbox. Use a towel to protect the playfield and backbox.

Playfield in Full Service Position

2. Unscrew all the switch stacks one by one. Wrap each switch stack in low tack masking tape or thread a 5-40 nut onto each screw to hold the switch stack together.

3. Undo the coil from the target bank. Don't let it just hang by the wires, tie it up with a piece of wire, string, tie wrap or old rubber ring.

4. Remove the screws that hold the target bank to the bottom of the playfield and pull out the target bank.

Teardown – NOTE take more pictures than you will ever need. You will still not have enough.

Rebuilt bank on the left, dirty bank on the right. Note, I helped myself out a little here, in that this was the third bank I did (so I had practice) and I had an exact target bank to reference. Not even a mirror image, which can make you stop and think for a bit.

Two Target Banks

Target Bank Ready for Teardown

The bank was completely off, some of the mounting brackets were loose from pulling it from the machine. The "front" and "back" of the target bank assume the bank is situated as shown, with the targets furthest from you. The side closest to you is the "front" and the side furthest away from you (closest to the targets) is the "back".

Drop Target Bank Teardown Procedure:

1. Remove the E clips on both sides of the rod

2. Remove the two plastic bushings that guide the rod

3. Remove the mounting bracket for the coil and rod

4. Remove the mounting bracket for the other end of the rod Note, you may need to slide the rod back and forth ¼ to ½ inch to accomplish this.

5. Remove the trigger arm return spring.

6. Remove the rod that runs through all the triggers.

7. Remove the front of the target bank.

At this point, you will have a sub-assembly like the one shown below. It should be fairly obvious that it is easy to pull off and reattach all those springs on the drop targets and triggers with the sub assembly as shown. One word of caution: Do not mix up the springs. The lighter weight springs attach to the plastic target. If you mix them up, the drop targets won't drop.

Target Bank Major Subassembly

8. Remove all the springs from the drop targets and triggers.

9. Pull out the drop targets

10. Disassemble the rest of the steel box (if desired for cleaning)

I feel that mechanical mechanisms work best when they are clean. They were not designed to work with a layer of grunge, oil and dirt on them, so I like to clean them up prior to re-assembly. If it is your first shot at this, you might want to minimize some of the disassembly and cleaning in favor of making sure you can get it back together. That said, I like to clean the face of the drop targets with Novus, then put a generous layer of carnauba wax over the hot stamped face for protection. Next, scrub out the nooks and crannies in all the parts with Mean Green and a toothbrush. Then, into the ultrasonic cleaner, if you have one, otherwise rinse off and blow the parts dry with compressed air. BE CAREFUL not to blow you parts all over the garage. You can put the little parts in an old sock or something when you blow them off. Wipe off the wax when dry. For the very small parts, like screws, you are probably better off not washing them at all, unless you have a lot of spare parts around.

• Drop Target Cleaning
• 

  Target Bank Completely Disassembled

• 

  Target Bank in Ultrasonic Cleaner

• 

  Target Bank Clean, Dry and Ready to Assemble

Target Bank Assembly Procedure:

1. Attach the "heavy" springs to the bottom plate

2. Attach the "back" (the side closest to the targets) to the top and bottom. Be careful and consult your pictures as it is easy to put the top on upside down, or mix up the top and the bottom. This is why you may be better off leaving these three sides of the steel box in place the first time you do this. ATTACH ALL THE SCREWS LOOSELY

3. Drop the targets in through the holes. No, you can't put the springs on first, they won't fit through the holes.

Drop in the targets and attach the springs to the targets.

4. Stick the triggers in through the targets. Make sure you have them right side up.

5. Attach the springs from the bottom plate to the trigger.

6. Attach the springs from the target to the trigger.

• Attaching Springs
• 

  Triggers in Place, all Spring Attached

• 

  Another View

Note: You can do the prior two steps in either order. You shouldn't need any tools to do it, but a needle nose pliers, a hemostat or even a small screwdriver may help you if you have sausage sized fingers. Once this sub assembly is together, the springs will hold the triggers in place.

7. Feed in the reset arm. Make sure you have it oriented correctly. Notes: You cannot feed it in after you attach the back plate. Also, on a very long bank, you may need to feed it in prior to attaching the springs from the bottom plate to the triggers. Take care on how you position the reset arm - make sure it is on the correct side of the stop screws in the bottom plate. With this method of assembly, it is fairly obvious though.

8. Attach the front plate. You may have to move the triggers around a little to get them to go though the proper slots in the front plate. This is fairly easy though.

• Assembling the Reset Arm and Front Plate
• 

  Feed In Reset Arm

• 

  Another View

• 

  Front Plate Attached

9. If there is a series arm, now is a good time to feed that in from one side or the other.

10. Now, feed in the arm through the guides in the front plate and all the triggers, the reset arm and the series arm. Leave the E clips off of both sides of the rod for now. You may have to wiggle the trigger arms a bit to get the rod to feed through.

11. Install the reset arm return spring.

12. Install rod support on one end of the assembly and the coil bracket/rod support on the other end. Install the plastic bushings on the end of the rods.

13. Tighten up all the loose screws.

14. NOW – finally- install those E clips!

Completed Drop Target Unit

Put the entire assembly back into the game. Clean up the backside of the switches that the trigger arms actuate when the targets drop. Gunk on those is a major reason what targets only go down half way. I like alcohol for this. Verify that all targets score. Verify that when all targets are down, the series bar pulls away from the NO switch (if you have one) and the switch scores.

Sit back, have a beer and congratulate yourself on a job well done, secure in the knowledge that you will not have to do it again for 20 years.

5.12 Power Supply Issues

Williams silicon bridge rectifier:

The function of the rectifier and capacitor is to convert the alternating current (AC) to direct current (DC), supplying DC to the bumpers, kickers, etc. The bridge rectifier should practically never need replacing as it is rated well over the voltage and current requirements of the components it supplies. If, however, the 15 amp 24 volt fuse on the mechanism panel opens, it could be due to a faulty rectifier. Disconnect the AC input to the rectifier, replace fuse, and recheck. If the 10 amp fuse located next to the rectifier opens, check all DC components I.E. bumpers, kickers etc. for shorts.

6 Test Procedures

6.1 Testing with a Jumper Wire

Details here: http://www.planetimming.com/Pinball/troubleshooting/EM%20Troubleshooting.pdf

7 Game Specific Problems and Fixes

Example would be servo controller on Independence Day pinball

8 Repair Logs

Did you do a repair? Log it here as a possible solution for others.