The Addams Family Pinball Machine Playfield Replacement

A playfield replacement is where the original wooden playfield, with the artwork, is replaced by moving all of the electronics and mechanical parts to a new playfield.  One of the most common reasons for doing this is the paint may have worn off portions of the original playfield.

The customer’s machine was originally shipped to Germany where it was played heavily and not maintained well until being re-imported into the US.  While all of the paint was still on it, there was a mylar (clear film) that was bubbling up over the inserts (the colored plastic windows for the lights). The ball would not roll down the playfield without encountering one of these bumps, changing the direction of it.

New playfield standing beside old playfield.

I’ve done about a half-dozen playfield replacements. The basic and generic steps are as follows:

  1. Take many photos of the top side, both close and from further back, and from different angles.
  2. Remove the playfield plastics and ramps (if any) and retake photos.
  3. Continue to remove everything from the top side of the playfield, clean all of the parts and set aside. Determine which items you’d like to replace such as pop bumper caps, plastic ramps, etc.
  4. Flip the playfield over and take many photos from different angles.
  5. Continue to detach everything from the bottom side. The goal is to slide the entire mess of wires, coils, lights and mechs onto a temporary surface such as a large piece of cardboard (I use plexiglass). Label each light socket and playfield switch. Leave everything soldered with the exception of pop bumper lights and outhole kickout solenoid (and any other wires going to the top side of the playfield). Remove all staples from any wires. Slide everything off the playfield onto another surface.
  6. Do any hammering next.  If there are pop bumpers you will have to carefully hammer out the captive screws without bending them. Then you will hammer them into the new playfield. Remove the wooden edge pieces and back panel from the old playfield and install on the new playfield.
  7. On the topside, install pop bumper housings and light sockets. This is done now because the ends of the light sockets will usually need to be stapled on the bottom side.  You’ll have to use a dremel tool with a small sanding drum to remove the clear coat from the center holes.
  8. On the bottom side, slide the mess of wires and mechs onto the new playfield. Do any stapling first while you can still move things around to get access with the staple gun.
  9. Install the screws for the remaining items on the bottom side. Sometimes the switches need precise placement and it’s best to drill pilot holes for the screws. On slingshots and eject holes, the arms and the solenoids are mounted separately.  The alignment is important to keep things from binding. Use the original playfield as a guideline.
  10. After everything is installed on the bottom side,  flip the playfield over and install all of the remaining items on the top side.


Bottom side of the new playfield almost complete.

During the Addams Family playfield replacement, all incandescent bulbs were changed to LEDs.  Also, spotlights and strip lighting were added.  Orange rubber rings and blue flipper rubber were used.

Top side of the new playfield being assembled. Rock wall decals were added to the back panel and the shooter lane ramp. (Click on any photo to see larger version)

Playfield lighting hooked up to a 6V power supply to test the General Illumination (GI) lighting. Jumper leads were used to power spotlights to determine the best position for them.

Completed playfield with various mods added, re-installed into machine.

TV mod at the top shows clips from the original TV series.

Swamp kickout on right has some purple and green LED strips. Likewise a LED lights up the pop bumper area.

Before installing the playfield into the machine, mirror blades were added to the sides of the cabinet. When it was all done, it looked like a brand new pinball machine. Just beautiful!


Last Action Hero Pinball Machine (Data East, 1993)

Symptom: not playing the correct sounds, some sounds playing backwards.
Location: Parker, CO

The pinball machine was playing most of the sounds correctly, but the background music wasn’t correct and at times played backwards, and sometimes Arnold’s voice callouts weren’t correct either. The sound test from within the machine’s test menu worked correctly.

I checked the electrical signals between the sound board and the MPU board with the oscilloscope and they seemed fine. I began to suspect a problem with the sound ROMs, so I brought the board back to my office where I could verify them, and they were fine.

At this point I dove deeply into the history and operation of the BSMT2000 sound system, which was developed by Brian Schmidt in the 1980’s. Supposedly “BSMT” is an acronym for Brian Schmidt’s Mouse Trap.  In any case, he developed sounds for many pinball machines in the 80’s and 90’s and also designed the sound system hardware. The hardware design was used by Data East, then Sega and then Stern. It’s basically a sample playback machine where the speed (pitch), looping, length and panning of a sound can be adjusted. From some of the sources I’ve read, up to 12 sounds can be played at once. It’s much like a digital sampling keyboard, but without the keyboard. The early boards were stereo with a center channel for the cabinet speaker.  Later circuits have parts eliminated and only monophonic is supported.

Since most of the sound board was working, I decided to create a test ROM that would test the RAM and then exercise the interface to the DSP (Digital Signal Processing) chip. Everything checked out okay, but I still had a sound board that wasn’t working correctly.

As I was staring at the schematic trying to figure out what else to test, I noticed “W6” and “W7” jumpers, which are connected to A18 of the sound ROMs.  On the schematic it says “W6 IS JUMPERED”.  The EPROM sockets will accept 27C010, 27C020, and 27C040 (1 megabit, 2 megabit and 4 megabit EPROMs, respectively).  Address line A18 is the highest address line for a 27C040 EPROM and when “W6” is installed, it connects it to +5V, which makes the socket only usable for ‘010 and ‘020 EPROMS.  But Last Action Hero has a ‘040’ sound EPROM. So what’s happening is it’s playing correct sounds from the upper half of the EPROM, and when it needs to play sounds from the lower half of the EPROM, it sees a duplicate data from the upper half. The lower half of the EPROM is inaccessible.

W6 and W7 jumper locations below the EPROM sockets (or above the sockets if the board is installed in the game)

It appears the schematics were never updated for machines that used 27C040 EPROMs, nor any other documentation to explain when the jumper should be installed in W6 and when it should be installed in W7.

So the rule is this: Any pinball machine with the 520-5050-0x sound board that is using a 27C040 EPROM, the jumper should be installed in W7 and not installed in W6. Any other situation requires the jumper to be installed in W6 and not W7. Do not install the jumper in both locations at the same time. It’s one or the other.

Some other machines that use this board and have ‘040 EPROMs are: Rocky and Bullwinkle, Tales From the Crypt, and Jurassic Park. I suspect that someone acquired this board from an older machine like Hook or Star Wars and put it into this Last Action Hero, without having the knowledge of the W6 and W7 jumpers.

Another word of caution:  I don’t think the BSMT2000 chips are the same across all the different sound board designs made over the years. For example, later sound boards have more EPROM sockets and the BSMT2000 chip would need to know that in order to utilize them. I don’t have any information as to tell the difference between the BSMT2000 chips and the version of the internal code.

Markings on BSMT2000 chip

Flip Flop, Bally Pinball Machine (1976)

Symptom: Not resetting, only adds players with start button.
Location: Littleton, CO

I’m always very happy when I solve a problem with a pinball machine that its had since it left the factory. This pinball machine would not reset when the start button was pressed. Instead it would add players. I was able to trace the problem to the #8 Cam-stack of switches on the score motor (the 8E normally closed contact to the reset relay coil).  There I found two wires on two leaf switch terminals that had never been soldered.  The wires were folded over the terminal, ready for soldering, but someone on the Bally production line must have gotten distracted. The wires were making a good enough connection for the machine to pass testing and shipped out to the first customer.  It’s unknown how many owners this machine has had over the past 40+ years, but I bet it was having this intermittent problem throughout its life.

I’ve probably come across a half dozen machines that have left the factory with issues. So far the machines have been in above average physical shape because they got pulled out of public service earlier due to their intermittent issues and sold to private individuals.  A few years ago I worked on a Gottlieb Circus that left the factory with a bad crimp pin connection in one of the connectors. The machine was immaculate.

Intermittent issues are very difficult to find, especially if the machine starts working correctly the moment I start tracing the problem. In this case I was lucky and the machine stayed dead until I found the problem.

Transformers, The Pin (Stern, 2012)

Symptom: Would not power up
Location: Firestone, CO

This is a home model pinball machine.  There is currently very little (none?) technical information about this pinball machine. It uses the Stern Spike system, which is used in some other professional machines and one other home machine (Avengers). I was unable to find any schematics for this machine or the individual boards. (I’ve read that Stern will be releasing some documentation in the near future.)

The machine would not power up. There is a 48 VDC power supply mounted inside the cabinet (you have to remove the bottom of the pinball machine to gain access to it). The 48 volts was working.

On the Spike MPU/Sound board (which is in the backbox), there are 4 LEDs to indicate the status of +48V, +24V, +8V, and +5V.  In this case the 5V LED was not lit. I found that D12 was shorted. Once D12 was removed from the board, I checked that D12 was truly shorted and it was. I also checked the pads where D12 was located, and it was still shorted there as well. This meant that the A8498 regulator chip (U30) was also bad. Once both components were replaced, I bench tested the board and all of the power status LEDs came on.

(Note: if the 5V is working, the +24V and +8V LEDs will only come on once the microprocessor has booted.  If the 5V is not working, then they will light regardless of the microprocessor.)

Stern Spike MPU board, 520-5318-01, from Transformers

The following is a more detailed look at the power section for other repair people who have the expertise to repair surface mount boards.This only covers the power sections and not any other functions such as sound, the microprocessor, or the interface circuitry.

The 48 volts from the cabinet feeds the 24 volt, 8 volt, and the 5 volt regulator sections. Each of the regulator sections utilize an Allegro A8498 chip, which is a 3 amp switching step down regulator. The enable pin (pin 2) for the 24 volt and the 8 volt sections are connected elsewhere on the board.  If the enable pin is not 0 volts, the regulator will be disabled (turned off). The enable pin for the 5 volt section appears to be grounded so that it’s always enabled.

Each regulator section consists of the A8498 (Allegro A8498SLJTR-T), a 68uH inductor, a 60V, 5 amp Schottky diode (Comchip CDBC560-G), and some input and output filtering capacitors (470uF at various voltages).  Near each regulator is a test pad where the voltage can be checked.  The 5 volt test pad is near the reset button. Note that the A8498 has a thermal pad underneath the chip which is soldered to the board. Only a hot air rework station will remove this chip.

Each regulator section consists of the following components. Refer to the A8498 data sheet for details on how things are connected together.

5 volt section: U30, D12, L8, C132, C135, C133, C134, R106, R107, R108.

8 volt section: U10, D4, L6, C55, C56, C59, C60, R24, R23, R25

24 volt section: U6, D1, L5, C47, C48, C49, C50, R125, R16, R18

The output of the 5 volt regulator goes on to power three other regulators: 3.3V (U9), 1.8V (U31) and 1.0V (U32). These regulators are Rohm BD18KA5W, BD18KA5W and BD10KA5W respectively. There are no LED status indicators associated with these regulators, however there are test pads near each one to check voltages.

Transporter the Rescue, Pinball Machine (Bally, 1989)

Symptom: Machine is not working at all
Location: Greenwood Village, Colorado

The first problem the machine had were the batteries had been forgotten about. So the battery holder was replaced and new batteries were installed. All too common a problem.

While replacing the batteries, I noticed some burned circuitry.

Burned circuit in one of the pop bumper driver circuits

The burned driver circuitry was related to the lower pop bumper. Whenever I see this kind of damage, I always check the fuses.  Sure enough someone installed a 7 amp fuse where it should only be a 2 amp fuse.

Some of the fuses in an Williams System 11 pinball machine.

Out of the 6 fuses shown above, 3 were incorrect values, all higher than what they should have been.

The fuses are meant to protect against this kind of damage. Often in the history of a pinball machine, someone will replace a fuse with a higher rated fuse to keep it from blowing again without every investigating why the fuse blew in the first place. I’m not really sure why people do this. So instead of just simply having a blown transistor, the circuit board got damage and the pre-driver transistor, 7402 chip, and the coil were all damaged and had to be replaced. The 7 amp fuse never blew to protect the circuits.  Instead the transistor caught fire and burned until it acted as its own fuse and the circuit eventually opened.

The actual cause was the switch contacts on the pop bumper being adjusted too close together. Causing the pop bumper to energize continuously.

This wasn’t my customer’s fault. The blame probably goes to the operator who first purchased the pinball machine and placed in a public location to make money. A fuse or two probably blew and to keep the machine making money, installed larger fuses. Then eventually the pinball machine ends up in a home environment with the wrong fuses installed.


The Lost World Jurassic Park Pinball Machine (Sega,1997)

Symptom: Snagger releasing ball too early, or not lowering enough to grab ball.
Location: Lakewood, Colorado

The snagger mechanism on a Lost World pinball machine uses both optos and microswitches to determine the ends of travel.  Or more accurately, the microswitches are wired in series with the motor to cut-off the power when at one end or the other. The game MPU has no knowledge that this has occurred. The MPU instead uses the optos to determine when it is at one end or the other. So the microswitches are acting as safety switches to stop the motor if the optos fail or are unplugged, etc. The game code also has a timer to flag an error and disable the snagger if it doesn’t reach one end or the other in the allotted time.  When using the special test function in the Diag->Lost menu, the display will show the status of the optos, but relies on the switches to stop the motor at one end or the other. But during game play, the optos are used. So adjusting the switch levers had no effect.

Over time, the gears and belts develop mechanical play or slop. The original designer never accounted for this. The only adjustment is the center of travel, basically the flag that interrupt the optos. This can be loosened, rotated, and re-tightened on the motor shaft.  One could also loosen one of the pulley screws and accomplish the same thing. But this only adjusts the center of travel. If I adjusted it so that the ball would release and fall into the Jeep properly, the snagger wouldn’t lower far enough at the other end to grab the ball. If I adjusted it to grab the ball properly, it wouldn’t raise far enough and the ball would release on the edge of the Jeep and just sit there.

The largest source of play is the cam on the left side of the last hinge of the snagger.  As of this writing, Marco Specialties sells the shaft and the end housing of the snagger.  I wasn’t able to remove the last pulley due to damage of the set screw, so replacing it wasn’t an option.

What is really needed is a way to move one of the optos so that the motor runs a little bit longer to account for the slack in the mechanics.

I removed one of the optos and with a very small Dremel bit, created slightly curved slots for the opto leads in the circuit board. This would allow for the opto to be adjusted.

Showing new position of opto before final adjustment in the machine.

Added wires to leads to allow for movement

After determining the ideal position for the opto and adjusting the center travel (as mentioned above), I put a little drop of hot-glue on the top side of the board at the end of the opto to hold it in place.

The snagger now works perfectly.  Not the prettiest solution, but sometimes things need a slight design tweak. If there were more Lost World machines out there, I’d design an aftermarket board that would make this a lot easier.

Wizard of Oz Pinball Machine, Jersey Jack (2014)

Symptom: Version 2.0 LED Board replacement project
Location: Parker, CO and Highlands Ranch, CO











Diagram of positions of light boards next to playfield.




Drill with bit extension to reach tight areas.





Revenge From Mars Pinball Machine (Williams, 1999)

Symptom: Would not boot up.  Machine appeared dead.
Location: Littleton, Colorado.

Revenge From Mars is one of two pinball machines using the Pinball 2000 platform, which combines pinball and video. A video image is projected down onto a special playfield glass which merges video action with pinball.

The pinball machine is controlled by a customized personal computer platform. The machine uses a CRT for the video projection. Both the PC and CRT have many failure points.  Parts to repair the PC are scarce, as are people who can repair CRT monitors.

This particular pinball machine had been upgraded to an LCD monitor and a modern PC.  The PC was running software provided by Nucore, which allows the custom Pinball 2000 system to be emulated on commonly available PC hardware.

Pinball 2000 Nucore system

After checking some voltages, it appeared power was going into the PC, but nothing was happening beyond that point. So I ordered a new power supply and installed it, and it was still dead. I was expecting to have to replace the PC motherboard.  As a last ditch effort, I decided to check the CMOS memory battery. The battery was dead, but I had never encountered a PC that wouldn’t power up due to a dead battery.  I replaced the battery and surprisingly it powered up.  Most PCs will still power-up with a dead battery, but you get a message from the BIOS saying there is a problem with the CMOS (or NVRAM), and it often hangs before booting the operating system.

Coin battery for CMOS RAM

The motherboard is a Foxconn A6VMX series.

Once the PC was powered up, I had to go through several settings in the BIOS and change their default values:

Power State: Power ON
Halt On: All Errors But…
Keyboard: Enabled
Mouse: Enabled
Floppy: Enabled

Under Peripherals:
The parallel port mode should be EPP
Address: 378

The above settings will allow the system to start as soon as power is applied, and will skip checking if the keyboard, mouse and floppy are present.

Once the system was booting up, I discovered a number of switches and lights not working.  I replaced a couple of switches that were broken and adjusted the ones that weren’t working. For the lights, every one of the light boards had cracked solder joints at the input connector, which often resulted in the entire board not working. This is a common problem on most late model Williams machines using circuit board mounted 555 bulbs.


There has been some legal drama surrounding Pinball 2000 emulation systems.  Nucore developed the system, but were found violating the GPL open source license. At around the same time someone removed the copy protection and distributed the Nucore software for free as Pinbox.  Nucore and Pinbox are the same thing. Nucore is back with an updated version, but currently without the licensing to make copies of the original pinball 2000 ROMS, which are required to run the emulation.

Moving a Pinball Machine?

One of the questions I get asked the most is how to pack up a pinball machine for moving. There are several different approaches, depending on whether the head (backbox) folds down with a hinge or not. Generally, pinball machines made after the mid-1980’s have a hinged backbox.

Hinged Backbox (machines newer than mid-1980s)

  1. Remove all loose items from inside the machine such as the ball(s), coin box, manuals, everything!  Some machines have an option in the test menu to eject all balls from the machine.
  2. Open up the backbox and remove any large bolts holding the backbox to the neck of the cabinet.  Some of these bolts might look like a large wing-nut.
  3. Close up the backbox.  Make sure the inner door is closed and latched tightly, so it doesn’t rub on the backglass.
  4. Unlatch the backbox.  On a Bally/Williams machine, this might look like a suitcase latch.  On Data East/Sega/Stern, you will need to insert a large Allen wrench into the hole on the back and rotate it.
  5. Carefully pull the backbox towards the front of the game, while ensuring the cabling between the lower cabinet and the backbox is not getting hung up on anything.  There should be enough slack in the cables to allow the backbox to rest on top of the playfield portion of the lower cabinet.
  6. Note where the backbox is being supported by the lower cabinet. Place some cardboard, Styrofoam, towels, or other padding material in between to keep both the lower cabinet and the backbox from damaging each other.  This is usually at the very top of the backbox and the edges of the lower cabinet. Do not lay any packing material that would put pressure on the backglass.
  7. With straps, rope, or plastic stretch-wrap, tie or wrap the backbox to the lower cabinet so that the backbox can’t be lifted off of the cabinet.
  8. Place a chair or your knee under the rear of the lower cabinet and remove the rear legs, by removing both bolts in each leg.
  9. Lower the rear of the cabinet to the floor and then stand the pinball up on end so the coin door is facing up.
  10. Remove the front legs by removing both bolts in each leg.
  11. Keeps all of the bolts, balls, etc., in a safe place so they don’t get lost.
  12. With the machine on end, a dolly/hand-truck can be used to move the machine.

To reassemble the pinball machine, just reverse the process.

If you are shipping the pinball machine to another location, Contact NAVL (North American Van Lines) as they seem to have quite a bit of experience shipping pinball machines.

Detachable Backbox (machines older than mid-1980s)

  2. Open up the backbox. Label and disconnect the electrical connectors between the backbox and the rest of the machine.  On an EM machine there will be 2 or 3 large connectors.  On a solid state machine, you will either have to disconnect the plugs from the circuit boards (Bally), or there may be in-line connectors in the neck of the cabinet (Williams and some Gottlieb) that will need to be pulled apart.  You may leave connections that just go from one part of the backbox to another.
  3. Remove the 2-4 large bolts holding the backbox to the neck of the cabinet.
  4. Close up the backbox.  If you have a solid state machine, make sure the inner door is closed and latched tightly so it doesn’t rub on the backglass.
  5. Lift backbox from the lower cabinet.
  6. The power cord can be carefully stuffed down into the neck of the machine.
  9. Remove the front legs by removing both bolts in each leg.

To reassemble, simply reverse the procedure.  Take care to put the power cord back into the notch (this varies from machine to machine) before setting the backbox back onto the cabinet. Also take care in reconnecting the connectors to their original locations.

Note: Some people like to treat detachable backbox machines as they would a hinged backbox, by leaving everything connected, laying the backbox facedown on the lower cabinet, and securely wrapping or tying the backbox to the lower cabinet, as if it had a hinge.  But you need to make sure the backbox doesn’t move at all, so that it doesn’t pull on the wires (plastic stretch wrap would be best for this). This might be desirable if you are shipping a machine. But if you are moving a machine, it might be easier to move it as two pieces.


F-14 Tomcat Pinball Machine (Williams, 1987)

On F-14 Tomcat pinball machines, there is a light board mounted on the right side of the back wall of the playfield.  This light board holds the 6 flashers that are under the red (or white) domes.  Almost every F-14 Tomcat pinball machine I’ve worked on has had a damaged light board.

Original F-14 Tomcat light board with broken sockets.

Original F-14 light board, with damaged circuit board traces and someone’s attempt at fixing them.

The Williams part number for the circuit board is 5768-12151-00.

After searching around for an after-market replacement, and not finding one, I decided to design and make a new one.

New replacement board by Peak Pinball at the bottom.

The new board features #906 wedge type sockets with “L” brackets for support, beefier circuit board traces, repositioned connector and LED type flasher bulbs. I installed the new board into my customer’s machine and it worked perfectly.

(I no longer have have boards for sale.  I currently don’t have plans to manufacture more boards because there isn’t enough interest.)