West Slope Lubrication Tour

Locations: Basalt, Colorado; Grand Junction, Colorado.

First stop was to work on a Wurlitzer jukebox model 1100 (1948). Like many 1940’s Wurlitzers I’ve worked on, the selector shaft and heart-shaped cam was not rotating due to lack of recent lubrication. This causes it to play one selection regardless of what was selected.  Unfortunately, it’s not an easy thing to get freed up, and takes a lot of exercising and time.

The jukebox needed some other adjustments, such as the turntable height and the clutch. I replaced the line cord because it was in very dangerous condition. The color cylinder plastic sheets were also replaced.  This was an original, un-restored 1100 in good condition.

Next stop was to work on two Williams electro-mechanical (EM) pinball machines, Grand Prix and Aztec (both 1976).  The main problem with these machines were the stepper units were not freely ratcheting up and down. This is the number one problem with EM pinball machines.  A quick disassembly, cleaning and lubrication fixes the problem.  Occasionally the spring tension needs to be adjusted.

The Aztec was missing some electrical parts, which can’t be obtained unless someone is parting one out.  But I got it working as best I could.

Next stop was an AMI jukebox, model A (1946), which is also known as the Mother of Plastic. The selection mechanism was frozen due to lack of recent lubrication.  Like the 1100 above, it took a while to get it unfrozen and moving freely.  The selection buttons needed some contact cleaning and lube (buttons would stick when pressed). The tonearm wire where it plugs into the amp needed to the resoldered.  All in all, a great sounding jukebox.

It was satisfying to breathe some new life into these old machines.

Alien Poker Pinball Machine (Williams, 1980)

Location: Boulder, CO
Symptoms: Incorrect sounds

The sounds on this pinball machine were working when the machine was first turned on.  But after a very short time, the sound would go wonky.

After some discussion with the owner, we determined that the sounds themselves were not defective, it was just the wrong sounds playing at the wrong time.  For example when hitting a particular target you’d hear the ball drain sound rather than a speech clip.

Pressing the self-test on the sound board yielded all of the correct sounds.  This indicated that the sound select signals from the MPU board were not correct.  With the oscilloscope, I looked for pulses on pins 10-14 on IC 10 on the sound board, while the owner triggered things on the playfield.  Some signals were missing.  When I checked the same signal at J3, they were present.

The culprit was cracked solder joints on the connector.  In the photo below you can see cracked solder around the top three and the bottom three pins on the connector.

Cracked solder joints on connector pins.

Cracked solder joints on connector pins.

At the owners request, I pulled all of the boards out of the backbox and touched up any solder joints that looked suspicious.  After that, the proper sounds sounds played at the proper times.

 

Disco Fever Pinball Machine, Williams (1978)

Location: Windsor, Colorado
Symptoms:  Wouldn’t boot.

The owner didn’t realize there were batteries in the backbox.  And of course they were leaking.  I removed the battery holder from the board and fortunately the board hadn’t been damaged by the alkaline. I replaced the RAM chip with an AnyPin NVRAM module so that forgotten batteries wouldn’t be an issue again.

The machine booted up fine after that.  I did a quick “shop” job on the machine, replacing rubber rings, burned out lamps, and cleaning the playfield.  There is a broken pop bumper cap, but I am unable to find an exact replacement.

Pop bumpers, with target in the center and arrows/triangles around edge.

Pop bumper caps, with target in the center and arrows/triangles around edge.

 

Hurricane Pinball Machine (Williams, 1991)

Location: Littleton, CO
Symptoms: Sound problems, ferris wheel getting stuck, backboard spinner not working, backboard and playfield G.I. lights not working.

One of the ferris wheels was binding causing the belt to slip. I loosened the belt from below and spun both wheels.  One turned freely, the other did not.  I removed the e-clip, a washer and cleaned the shaft of sticky lubrication. The problem seemed to be the washer, which was too thick and causing to much friction when the e-clip was on.  I also noticed that the other wheel didn’t have washer, so I left it off.

The sound kept cutting in and out after the machine warmed up.  It would be on for a half-second, off for a half-second, repeat.  I pulled out my oscilloscope and checked the inputs to the amplifier. The input signal looked fine.  I disconnected the speaker and bypassed the digital volume control just to make sure the problem was with the amp IC. It seemed it was definitely the amplifier IC.

The backboard spinner wasn’t working.  It seemed like it was jammed.  I took the motor off of the back and shot some lubricant into the gear box.  That seemed to get it working again.  For how long, I don’t know.  The owner declined to replace the motor and gearbox assembly.

The playfield lighting problems were related to a burnt connector, which I see all of the time.  I replaced both the PCB connector and the wire connector and the lighting is now working great.

I took the sound board back with me since I didn’t have an amplifier IC with me.  A few days later, I shipped the repaired board back to the owner, who installed it and said it’s working perfectly!

 

Black Knight Pinball Machine (Williams, 1980)

Location: Fairplay, Colorado (home of South Park).
Symptoms: Speech only, but no background sound; Multi-player bonus round not working; Some drop targets not resetting.

I tackled the sound problem first.  When I started the game the speech was working fine, but the background sound effects were not there.  I checked the connections to the speech board.  On this era of Williams machine, the analog sounds leave the main sound board and go to the adjacent speech board, where the analog sound and speech are mixed together.  Then the sound travels back to the main sound board for amplification and then to the speaker.

The connections were all good.  I disconnected the speech board and jumpered W1.  This will send the analog sounds directly to the amplifier, bypassing the speech board.  Still nothing.

With my oscilloscope, I could see the sound coming out of the digital to analog converter (IC13). From there it goes to a transistor (Q2) which acts as a current to voltage converter.  The transistor was acting like it wasn’t connected. I pulled it from the circuit and tested it with my meter and determined the transistor was bad (normally they short when failed, but this one was open).

D/A converter with Q2 transistor.

D/A converter with Q2 transistor.

I replaced the transistor, and for the first time in 5 years it made sound!

Next, I decided to check the drop targets.  A couple of the drop targets in the middle bank would pop up during reset, but would not stay there. This turned out to be a missing screw that held part of the assembly together.  I found the screw in the coin box and reinstalled it.

Next, I noticed problems with other switches in the matrix.  I removed the balls from the machine and ran the switch diagnostics.  It showed that switches 5, 13, 21, 29, 37, and 45 were all closed. They all share the same row (White/Green Row 5). so it looked like they were shorted to ground someplace.  To isolate whether the problem was in the machine wiring or with the driver board circuit, I unplugged 2J3.  The diagnostic still showed the switch row shorted to ground.  IC16 was bad.

The shorted switch row was the reason the multi-player bonus round was not working.  One of the switches in that row is the shooter lane, so the machine always thought there was already a ball there and wouldn’t deliver another to the shooter lane.

The switches all worked once IC16 was replaced.  Next I solved some minor connection issues with the flippers and G.I. lighting.  The Black Knight was ready for battle again!

 

Fairplay, CO, aka South Park. Cartman's face is missing.

Fairplay, CO, aka South Park. Cartman’s face is missing.

 

Flash Pinball Machine (Williams, 1979)

Location: Erie, CO
Symptoms: Pinball machine “goes crazy” during play.

I played the machine and the “goes crazy” aspect seemed to be something related to the switch matrix.  I put the machine in Diagnostic Mode and checked the switch status. It seemed to be a row of switches was grounding out intermittently.  The switches would work fine then suddenly there were 4 or 5 stuck switches.

I found the problem at the coin door, with one of the coin switches shorting out against the coin mechanism.  The coin switch was looking pretty beat-up because the owner, or the previous owners, didn’t know how to put Flash into freeplay mode.

With these early solid state machines from Williams, you can put the game into freeplay mode by following these steps:

  1. In game over mode, open the coin door and switch the Up/Down switch to UP.
  2. Press the Advance button.  The Credit/Ball display should show “04 00”.
  3. Keep pressing Advance until the display shows “04 18”. This is the Maximum Credits setting.
  4. In the player 1 display you should see a current value of 20 (default).
  5. Switch the Up/Down switch to Down.
  6. Press the Game Start button (not the Advance button) until the number in the player 1 display is “00”
  7. Press the Advance button, then turn off the power.  When you switch the power back on, it will be in Freeplay mode.

After fixing the short, a few switches needed cleaning and adjusting.  The machine was working fine at this point.

About 2 weeks later, I was called back because the machine was skipping balls, for example going from Ball 1 to Ball 3.  I determined that there was a really sensitive switch on the playfield causing scoring without even shooting the ball.  That, combined with a mis-adjusted ball trough switch, was causing the problem.  The trough solenoid would fire the ball to the shooter lane, and the vibration would cause the sensitive playfield switch to close causing it to score, and the ball trough switch would still be closed because the ball hadn’t left the trough yet.  The machine “thought” the ball had been shot, scored and drained all in a split second, giving the appearance that the ball was skipped.

Once the switches were adjusted, the game was working fine again.

Whirlwind Pinball Machine (Williams, 1990)

Location: Highlands Ranch, CO.
Symptoms: Ramps tries to lower even though it’s already down; delivers two balls into shooter lane.

After checking the mechanical operation of the ramp and running switch tests, I concluded (or guessed) that the microswitches on the ramp and ball trough were acting intermittently.

Sometimes when a machine acts weird like this, you have to think about what the firmware is attempting to do.  In the case of the ramp, it tries to lower the ramp because it hasn’t sensed that it has been lowered.  So it would keep trying 4 or 5 times before giving up.

The reason the computer was delivering two balls to the shooter lane is that it wasn’t sensing the first ball had actually made it to the shooter lane, so it would try again.

Both of these problems weren’t consistent which led me to the intermittent switch idea. The microswitches were probably dirty and worn inside.  Unfortunately, since they are totally enclosed they can’t be easily cleaned.  Sometimes I can flush the switches out with contact cleaner, and get them working again.  In this case, it worked!

Funhouse Pinball Machine (Williams, 1990)

Location: Up Poudre Canyon, west of Fort Collins, Colorado.
Symptoms: Needed to be “shopped” (basic restoration).

This pinball machines gets the award for the worst leaking batteries I’ve ever encountered.

Forgotten batteries causing a lot of damage.

Forgotten batteries causing a lot of damage.  Click for larger.

The corrosion was so bad that the battery holder nearly fell off the board when I started cleaning it up.  The corrosion had eaten through the metal pins that hold the battery holder to the board.  As you can see from the photo above, the corrosion was also affecting the nearby circuitry.

I finished removing the battery holder from the board and flushed the board with white vinegar and scrubbed with a toothbrush.  The vinegar helps to neutralize the alkaline. After letting the board dry out for several hours, it still was able to boot up.  I installed a remotely mounted battery holder on the inside of the backbox, where if the batteries leak in the future, it won’t damage anything.

I “shopped” the rest of the machine, replacing rubbers, cleaning the playfield, and replaced the bad bulbs.  The machine is working great and looking great.  I’ve now worked on more Funhouse pinball machines than any other model, breaking the previous record held by Star Trek: The Next Generation.

 

No Fear: Dangerous Sports Pinball Machine (Williams, 1995)

Location: Castle Rock, CO.
Symptoms: Needed to be “shopped” (basic restoration).

The biggest problem that this machine had, which I’ve come across a lot lately, is forgotten batteries.

Batteries dated 2006 badly leaking and damaging the battery holder and switch connector (not shown).

Batteries dated 2006 badly leaking and damaging the battery holder and switch connector (not shown).

Fortunately, on the WPC-95 systems, the batteries are mounted on a separate piggy-backed board which saved the CPU board from certain death.  But even so, the alkaline affected the cabinet switch connector located right next to the batteries.

The battery holder was removed and the RAM chip at U8 replaced with an anyPin NVRAM module that doesn’t require batteries.

The playfield was cleaned, all of the rubber parts were replaced, as well as the slingshot plastics.  The machine is looking good and playing well.

Terminator 2: Judgement Day Pinball Machine (Williams, 1991)

Location: Castle Rock, Colorado.
Symptoms: Machine needed to be “shopped” (basic restoration).

The owner had just purchased the pinball machine from an acquaintance. The playfield was one of the dirtiest I have ever come across.  Fortunately, with a lot of elbow grease, Novus 2 polish and some Mill Wax, I was able to get the playfield looking pretty good.

To clean the playfield and replace all of the rubber parts, the ramps had to be removed, then replaced.  This is time consuming, but was worth doing.

I installed a new flying hunter killer ship kit for the playfield, since it was missing.

The pinballs were replaced with new ones because the existing ones were badly pitted.  The main reason the balls were badly pitted was that the left side kickback was badly damaged. Each time it would fire, it would slam, metal to metal, against the ball, making small pits in it.  The metal that was on the ball would come off and wear into the playfield.

Damaged kicker on left, new kicker on right.

Damaged kicker on left, new kicker on right.

By the looks of it, this kicker had been broken for years. Never allow any device that comes in contact with the ball to go un-repaired.  The playfield is the most valuable asset in a pinball machine and pitted balls will shorten its life.

The switch on the cannon was intermittently bad.  Usually it’s the wires that have broken after the cannon has twisted them back and forth thousands of times.  But in this case, it was the switch itself.  It was replaced.

It goes without saying that any burned out bulbs were replaced.

By the end, the pinball was playing well and looked great.  Some of the mylar on the playfield is bubbling and that will have to be addressed at some point in the future. The biggest problem with removing it will be that the decals on the playfield inserts will not survive the process and I haven’t seen any decal sets for this machine.