anyPin NVRAM module

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When I was at the Pinball Showdown a few weeks ago, I picked up a couple of anyPin NVRAM modules from Rob at Pinball Classics (he had a booth there).

All pinball machines made prior to about 2000 use some type of battery system for maintaining the settings and high scores.  The batteries often leak and cause damage.

The “NV” in NVRAM stands for Non-Volatile, which means it will remember its contents with no power.  It uses a ferroelectric technology where the RAM contents are stored in tiny magnetic charges.

anyPin NVRAM module by Pinball Classics

anyPin NVRAM module by Pinball Classics

Since the Showdown, I’ve installed the modules in two of my customer’s machines.

The first machine was a Bally Bobby Orr Power Play in Windsor, Colorado. The CPU board in this machine had the original Ni-Cad rechargeable battery installed. It was leaking white alkaline from the ends. I de-soldered the battery from the board and installed the NVRAM module.  It worked right at startup; no other configuration was needed.

The second machine was The Games by Gottlieb located in Brighton, Colorado.  This uses the Gottlieb Systems 80A system.  Like the Bally, it has a rechargeable battery. The battery itself didn’t look too bad after 30 years of use.  But it would have started leaking soon.   The other problem is the customer doesn’t leave the machine on long enough to charge it up.  Powering up the pinball machine a couple of hours a week is not long enough to keep those batteries charged.

The old Gottlieb RAM chip was soldered on the CPU board, so I had to remove it, then installed the socket strips that come with the module.  (That machine also had a bad display driver chip that needed replacing.)  Everything worked flawlessly at power-up.

Williams and Stern pinball machines use AA batteries to remember their settings.  They leak if you forget about them.  I’ve got a customer with a Williams World Cup Soccer where the batteries leaked because the machine was in storage for a number of years.  The alkaline from the batteries ate through the tin plating on the battery holder and now there is a very unreliable connection to the batteries.

I can’t recommend these anyPin NVRAM modules enough!  Most of the machines I work on have some type of battery issue and this module is the long term solution.

Creature from the Black Lagoon Pinball Machine (Bally/Midway, 1992)

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Location: Centennial (Denver), Colorado.
Symptoms: Blows fuse on power up.

When powering up the machine, the F114 fuse (8 amp) would blow.  This fuse powers the lamp matrix as well as the CPU +12 volt circuit through a downstream fuse (F115), which is used for the switch matrix.  So when I first power up the machine, the CPU was booting but none of the lights were flashing and the switches on the coin door were unresponsive.

I disconnected all of the lamp matrix connectors from the Power Driver Board (J133 through J138) and powered up the machine, and the fuse blew again. Since all of the connectors were disconnected and fuse F115 wasn’t blowing, the problem had to be in the power supply itself.  There are only two possibilities, a shorted bridge rectifier or a shorted capacitor (rare).  I check the bridge rectifier and it was shorted between “AC” and “+”.  I had a spare bridge rectifier on hand and replaced it.

The machine powered up as normal this time.  A lot of the matrix lamps weren’t working.  I replaced a bulb near the flippers and it still didn’t work.  I thought maybe a row or column driver had failed.  So I ran the test for individual lamps and marked a copy of the matrix with an “X” if the lamp wasn’t working.  No clear pattern emerged to indicate a row or column problem.

So I started at the first bulb in the test and looked at each one.  It turned out that most were burned out.  Also, I found a broken wire for Row 1 of the matrix.  Reconnecting that got about 6 more lights working, including the first bulb I had replaced where replacing it didn’t help.  It’s a tedious process, but in the end the machine looked and played well. I probably replaced two-dozen bulbs.

White Water Pinball Machine (Williams, 1993)

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Location: Centennial, CO
Symptoms: Flipper problems.

The owner previously knew the lower right flipper coil was bad, so I had a replacement on hand when I arrived.  After replacing the coil, I checked all of the fuses on the Fliptronics board and found one blown and another fuse as the wrong value.  All four fuses should be 3 amp slo-blo (MDL type).

I powered up the machine and found that the flipper was often sticking in the up position.  Before the coil went bad, this was one of the original complaints.  It wasn’t a mechanical sticking, but the hold coil was staying energized when it should have released.  I tracked the problem down to the flipper opto board.  The bottom edge of the board wasn’t was tightened down all of the way.  The board was just twisting enough that it would move slightly when the flipper button was pressed, then it didn’t detect the button being released until some vibration in the machine caused the board to move a little.  I tightened the mounting screws and that problem was solved.

The upper right flipper was kicking but not holding.  It looked like all of the wires were connected to the coil and the terminals were wrapped in electrical tape.  So I looked at the Fliptronics board and checked the voltages coming back from the flippers.  When the game is powered up, in play mode, and flippers is NOT energized, 70 volts should be present on every terminal of J902 that has a wire connected to it (it varies from game to game based on the number of flippers).  This is a good way to check coils and connections.  In this case, there was no voltage present on pin 4. That verified that there was an open connection in the coil or the wiring.

So I went back to the coil for a closer look. I unwrapped the tape and found that the terminal strip on the end of the coil bobbin, where the connections are made, was broken.  It was the reason why it had been taped. The fine gauge wire used in the winding of the hold circuit had broken inside the coil.  Some coils can be repaired if the broken wire is on the outside layers of the coil, but in this case it wasn’t.

I generally don’t stock flipper coils, so I would have needed to order it. The owner elected to buy a new coil at the Pinball Showdown, which is happening this weekend in Denver.

Not all flipper coils are created equal for the Williams pinball machines.  Each pinball machine was designed to use specific coils based on what the coil needed to accomplish in each game layout.

  • FL-11753 Yellow – Used with short flippers and close shots
  • FL-11722 Green – Used for close shots near drop targets
  • FL-11630 Red – The standard, most commonly used coil
  • FL-15411 Orange – Used for long playfield shots
  • FL-11629 Blue – Used for long shots and high ramps

In the case of White Water, the blue coil is specified as the lower right and the red coil is specified for the upper right.

The Games Pinball Machine (Gottlieb, 1984)

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Location: Brighton, CO
Symptoms: Pop bumper not working, display digit not working, needed cleaning and tuneup.

The machine was good condition.  I should have taken photos because the photos in the IPDB are of a machine in very poor condition.

The non-working pop bumper was simply a broken wire going to the coil. I resoldered it.  I checked the other pop bumper switches and noticed the top bumper’s switch was sticking.  If you press down on a bumper skirt and it doesn’t immediately pop back, you’re asking for a burned-out coil.  I cleaned the spoon that the bumper skirt rests on and that seemed to help a lot.  Often the pointed end of the bumper skirt that contacts the spoon gets roughed up and needs to be sanded or filed smooth and round again.  It’s a pain to do because it’s difficult to get to, and often involves removing it which requires taking the whole assembly apart.

The display on Player 3, least significant digit, was dead. I checked the card edge connector and made sure the card edge was clean.  I fired-up the oscilloscope and saw that the pulses (4 volt) were going into the digit driver IC, but no 60V pulses were coming out of the pin for that digit.  The other digit drivers within the IC were working fine.

The IC is a UDN6118A, which is no longer made.  These can the purchased used on E-bay from Chinese distributors. There was also a new one available at a US chip broker, for $15, plus $8.99 shipping.  Does it really cost $8.99 to ship something that weighs as much as a paper clip?  No!  For the same price, I can get 5-10 used chips from China.

For the time being, I swapped the Player 3 and Player 4 displays because the owner said the Player 4 gets used less often.  The owner is contemplating whether to repair the display or live with it.  I was surprised to see that PinScore doesn’t make aftermarket displays for Gottlieb (and neither does anyone else that I could find).

I also advised the owner that the rechargeable battery on the System 80A control board should be replaced before it leaks and ruins the circuit board.

I replaced bulbs and did a quick cleaning of the playfield.

When I played the game, I thought the sound board had something wrong with it.  There was a lot of background noise.  But it turns out the background noise is supposed to be crowd noise like at a stadium.  I verified by watching a YouTube video of the same machine.  You have to use your imagination.  I think it would have been better to have some background music with an Olympic theme.

 

Space Invaders Pinball Machine (Bally, 1980)

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Location: Near Morrison, CO.
Symptoms: Blows fuse (F4).

The machine would immediate blow the fuse (less than 1 second) upon powering up.  Fuse F4 supplies the 43 volt solenoid circuits which are prone to broken wires, shorted coils, etc.  So, I expected to find a short somewhere on the playfield.   I isolated the power supply by removing all of the connectors except for J2 (cabinet) which supplies the wall AC power to the power supply, but this connector also supplies solenoid power to the knocker and the coin door.  The fuse still blew.  I checked the cabinet wiring to make sure there was no short, then focused on the power supply itself.

It turned out to be a shorted bridge rectifier between the AC and the minus (-).  I brought the power supply back to my shop for repair.  I looked up the part number for the bridge and found it on Marco’s site.  For better or worse, the bridge I received was slightly larger.  Not only were the pins further apart, it was also thicker.

New bridge rectifier (black square) above an original working bridge rectifier just below it.

This posed a problem as there are two bridge rectifiers in the circuit and both are mounted on the bottom side of the PCB and are heat-sinked against a metal bar on the power supply chassis.  If one is thicker than the other, one will be heat-sinked, the other will not.

I decided to shift the bar over, so that existing bridge would contact the bar and the new bridge would go directly to the chassis.

With the metal bar, both rectifiers will contact the chassis when the board is remounted.

I added some new heatsink grease to both bridges.  I powered the circuit and all was fine.  This power supply was only used on two machines, KISS and Space Invaders.

Back at the customer’s location, the game powered up and worked fine.  I replaced a few burned out bulbs.  The NiCad RAM backup battery mounted on the CPU board has partially failed. I am debating whether to replace it with a 1 farad super cap, or the typical 3 cell AA holder.  The super cap requires the machine to be powered up periodically so that it can recharge.  The AA batteries don’t require recharging, but there is no nice place to put the battery pack and they have to replaced every few years.

 

Funhouse Pinball Machine, Williams (1990)

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Location:  Greeley, Colorado.
Symptoms:  Many.  Bulbs out, trap door not working, a pop bumper not working, both sling-shots not working, flipper sticking, etc.  Needed general servicing.

The biggest mystery with this machine was that every GI (General Illumination) bulb was burned out, except for 3.  I suspect that at some point in the past, there was a GI short to a solenoid supply which blew most of the bulbs.

As I was replacing some of the controlled lamps, I discovered some that were burning very brightly.  This raised a red flag that one of the rows or columns in the lamp matrix was stuck on.  The easy way to check this is to go into the test menu and run the single lamp test.  If more than one light comes on at a time, then the row or column driver is shorted or bad.   It turned out to be Column 8 and the TIP107 transistor.  All of the Column 8 lamps would light when any of the other columns were on.  After replacing the transistor, the controlled lamps all worked except one.

The one lamp that didn’t work was the “Open Trapdoor W/Flashing” light.  It was lighting when any other column or row was lit. In other words, the only time it acted normal was when any thing in its own column or row was lit. At first I thought it was a shorted diode.  The diode tested OK with the meter.  But the meter doesn’t test the diode at greater than 3 volts.  So I snipped it and the light should have gone dark, but it didn’t.  It turns out, someone had soldered the wires onto the socket incorrectly and bypassed the diode.  Once I corrected the wiring, it worked fine.

As for the sticking flipper, it was a bad link that was catching on the end of the solenoid.  I replaced the links, plungers and rubbers on both lower flippers.  The upper flipper looked good enough to leave alone.

The other solenoid problems were all related to broken wires.

The trap door wasn’t working because the end of the spring broke on the solenoid that latches it up.  I found the spring in the bottom of the machine and made a new hook with my pliers, and reattached it.

The game had an L4 version Game ROM (U6) installed.  The most recent official version is L9, plus there is an L9.05H, which is a home version with some additional features.  The difference between and L4 and L9H requires a move to a larger ROM (1 Mb to 2 Mb), plus one of the sound ROMs (U18) had to get upgraded to L3.

The L9H ROM images I downloaded from ipdb.org didn’t really match the documentation.  The U6 ROM image was a 4 Mb image, and U18 was a 2 Mb image.  In this Funhouse machine, both of these parts were 1 Mb so I couldn’t erase and re-program.  I was out of 2 Mb EPROMs.  So I ordered some blank 2 Mb parts from Marco and received 4 Mb parts instead. Ugh!  I looked at the schematic for the sound board and saw that it would support a 4 Mb ROM.  So, I programmed both images into 4 Mb EPROMs.  This works fine for U6, but for U18 it doesn’t work without loading the code into the upper half of the EPROM to make it look like a 2 Mb part.  Although the sound board hardware supports the 4 Mb ROMs, the firmware in the other sound ROMs doesn’t.

A note on CPU jumpers for larger ROMs:  I think by default, the early WPC games had the W2 jumper installed.  W2 supports the 28 pin ROM families and will still work with a 1 Mb 32-pin ROM because the associated pin on the 1 Mb ROM is not used.  But anything larger (2 Mb or greater) will need the W2 jumper removed and the W1 jumper installed.  The W1 jumper supports all of the 32-pin ROM families.  So when using a 1 Mb ROM, the jumper can be in either position.

The same is true for the sound board with regards to U18.  Jumper W4 supports the 28-pin families and jumper W3 supports the 32-pin families, with the 1 Mb ROMs not caring which position the jumper is in.  But keep in mind that at least for Funhouse, the sound system firmware doesn’t support anything larger than a 2 Mb ROM in U18.

After correcting dozens of small problems, the pinball machine is looking and working great!

Wurlitzer Model 3300 (1969)

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Location: Henderson, CO
Symptoms: Both record lifting arms jammed into the record carousel.  The carousel was unable to rotate.  Trip switch not working.

I spent a good half-hour trying to unjam the record arms from the carousel and realized there was no hope without total dis-assembly.  Both tips were bent over facing the rear of the jukebox.  I’m not sure how they got that way, possibly when the jukebox was moved to the basement.  I’m surprised the plastic tips hadn’t broke.  The only option was remove to the record playing mechanism from above the carousel, then remove the carousel.  I advised the owner that this was going to take several hours.  I got the go-ahead.

Once everything was disassembled, I noticed the three rollers that support the carousel were frozen.  A generous dousing of WD-40 didn’t solve the problem.  I finally took a pair of pliers and rocked the rollers back and forth sideways to break whatever corrosion or gunk kept them from turning.  That worked.  Then another dousing of WD-40.  I followed up with regular oil and all three rollers were spinning freely again.

The tips on the record lift arms needed to rebuilt after being jammed.  They are spring loaded and should open up as the arm rises into the carousel.  I disassembled each tip, cleaned, readjusted, and lubricated with silicone.

I put the mechanism back together and did a couple of trial runs with no records installed.  Everything seemed to be working great.

Once again, another bad trip switch.  I encounter these a lot on later model Wurlitzers.  As I have described here in this log before, I broke open the cover and flushed with contact cleaner.  It’s pretty much all one can do, as you really can’t get to the contacts themselves with any kind of abrasive. I reassembled the trip switch, adjusted it, and played several records.  Seemed to work okay after that.  On the jukeboxes I have done this, they are still working after nearly two years.  But still, it would be nice to find a replacement switch.

Amplifiers, Amplifiers, Amplifiers!

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In an odd quirk of fate, I’ve had a rash of jukebox amplifiers to work on, as well as some Seeburg control centers.  The amplifiers are a Wurlitzer 532, Seeburg TSA1, Seeburg SHP3, and an amp from a Rockola 424.  The 532 is the oldest and the SHP3 is the newest.

Testing a Wurlitzer 532 amplifier.

Wurlitzer 532

At the customer’s house, the 532 was exhibiting all kinds of problems.  The sound was popping, cutting in and out, and most of the time was severely distorted.  One of the items that was causing all of the popping was a bad connection in the octal socket between the mechanism and the amplifier.  The power to the amp runs out, and back in, through the connector (except for the tube heaters which are on all of the time).  Also the amp has a rectifier on it which supplies power to the mechanism.

Each female pin on the octal socket is shaped like a “U”.  Over the years with the plug being unplugged and replugged, the top part of the “U” spreads apart and doesn’t make a good connection with pin. I took a sharp ice pick and poked it down into the edges of each hole and bent each arm of the “U” so they would be closer together.  That solved that problem.

However, there was still a lot of distortion.  I opted to bring the amp back for a bench test.  With a bench test, I can inject a known signal and trace it through the circuit with an oscilloscope to see where the signal breaks down. In this case, it was bad at the output of the first tube in the chain.  It wasn’t a bad tube, but a bad electrolytic capacitor connected to the cathode of the tube.  The amplifier will be getting re-capped (replacement of all electrolytic capacitors).  It’s overdue.

Seeburg TSA1

At the customer’s house the amp was distorted especially in the lower frequencies.  Changing the volume had no effect.  It seemed to be in both channels.  There wasn’t good stereo separation.

I brought the amp back for bench testing.  There is a coil in the amp that connects the left and right channels together.  I’ve seen this in other jukebox amps of the late 1960’s, and it doesn’t make sense.  After I disconnected it, I discovered the distortion was only in a single channel.  And it took me a while to discover it as I had to drive the input fairly hard for it to show up.  And it was more prevalent at bass frequencies.  It looked like someone was taking a bite out of the lower side of the sine wave (it wasn’t at the peak).  After checking the bias and the caps around the preamp stage where the problem was, I concluded it had to be the transistor.  I replaced it, and the problems cleared up.  I chalk that one up to weird transistor failure.

Rockola 424 amplifier

The service manual calls this a 40276A.  The amplifier itself has 40218 labeled on it.  Regardless, one channel was completely dead.  The mono switch didn’t have any effect, so the problem was in the output stage.

I brought it back for bench testing. I quickly discovered the 1200uF capacitor used in the feedback circuit had a broken lead.  This amp had been previously worked on by somebody else and they had replaced the capacitor without securing it well.  The vibration of moving the jukebox to Colorado from the east coast probably caused it to break. Since the lead was broken right at the capacitor, it needed to be replaced.

While checking out the amp, I noticed some electrolytic capacitors where leaking.

Electrolyte leaking from capacitors.

Those 100uF capacitors got replaced, as well as the main filter capacitor (2940uF was replaced with a 4700uF).  After cleaning the preamp wirewound pots (not easy or effective), the amp is working well.

The Seeburg SHP3 amplifier will be covered in a future post about a Frankenstein jukebox.

Haunted House (Gottlieb pinball machine, 1982)

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Location: Wellington, Colorado.
Symptoms: Would blow fuse as soon as ball landed on lower playfield.

The problem was obviously a short related to something that powered the lower playfield.  I inspected the wiring and coils on the lower playfield and didn’t see any issues.  With the machine off, I checked for shorts in coil and flipper power wiring and didn’t see any.  I finally found the short with my meter in the playfield illumination wiring, and it turned out to be on the main playfield.

On the underside of the main playfield, there are 8 lamps that light the lower playfield. These lights only illuminate when the ball is on the lower playfield, and are controlled by a relay.  Next I did a visual inspection of each of the 8 lamps, and as usual, found the short on the last one I checked. 😉  The center contact was shorted against the side of the socket, which is typically where lamp circuits short out.

The owner had replaced all of the lamps with LEDs.  One important thing to note:  On Haunted House and Black Hole, these 8 illumination lamps are powered by 28 volts, which will blow out regular 6 volt LEDs.  The original bulb number is a #313. You either have to use an LED specified to replace a #313 bulb, or you have to modify the lighting circuit to operate on 6 volts (a procedure is here).

 

Wurlitzer 2104 jukebox (1957)

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Location: Lakewood, CO
Symptoms: Needle not contacting record, plays wrong selections.

We selected a record and the needle hovered about 1/8 inch above it.  I moved the tone arm and felt it binding.  I put some silicone lubricant on the tone arm pivots.  I also noticed the tone arm audio cable seemed to be a little tight which added to the binding.  I loosened the cable clamps and gave it another 1/4 inch of slack.

Usually when a Wurlitzer is not making the correct selections, the problem is either dirty switch contacts in the keyboard, or a lubrication issue with the pre-selection arm or disk at the bottom of the mechanism. Since this was probably the cleanest unrestored jukebox I’ve come across, I didn’t suspect dirty switch contacts.

On the ’04 models the pre-selection disk (I don’t know what Wurlitzer calls it) is used to differentiate the letter selections.  I call it pre-selection because this disk the first thing that begins moving when making a selection.  The disk rotates into position determined by a couple of solenoids, then fires one of the numbered solenoids visible around the edge of the mechanism. This disk rides on 3 nylon wheels, which often stop turning with age. I lubricated the nylon wheels and got them turning again.  The jukebox now made the correct selections.

One additional item was that I cleaned the volume control with potentiometer cleaner.