a note about rebuilding Gottlieb “fat boy” flippers

In general, I don’t rebuild Gottlieb “fat boy” flippers as part of shopping out a game. This is in contrast to Williams solid-state flippers, which do wear out. The exception is the EOS switch. The lever arm will chew a hole in it over a couple decades of play, and it’s worth checking first. It may be fine, or it may need replacement.  I have also seen the plunger/link crack apart. But otherwise, these flippers just work.

On my Monte Carlo and couldn’t make the Firepower-esque lock shot, up the left side and into a saucer. Without this shot, there’s no multiball, and no way to spin the roulette wheel. The flippers seemed fine otherwise, but were clearly missing some oompf.

I replaced the sleeve because it’s cheap and checked out the link assembly, which seemed to be fine. I decided to get more drastic. I have a couple MA-989 upgrade kits with NOS link assemblies and new EOS switches that should make the EOS switch also nearly indestructible. I decided this was a fine occasion to use one. Ultimately, I replaced the EOS and lane change switches, the coil, the coil stop, the plunger/tip, and the lever that clamps around the flipper shaft. Still, it was weak, and in fact it was a little worse.

But in the process, I had installed the flipper with an angle that was too horizontal at rest. I think I was working off the angle of the left flipper, which wasn’t necessarily right to begin with.  I went back and took a look the flyer and went for a droopier angle, and happily, I can make the shot!

I suspect that flipper mechanism develops a lot of power at the end of its stroke.  Plus, the angle made the flipper play funny, and I may have had a hard time adjusting.

I will keep all the parts I took out as spares—I don’t think they’re bad. And I will pay more attention to the angle in the future.

I am not enamored with the MA-988/MA-989 upgrade kits. They require some care to ensure that the return spring isn’t touching the switch. The geometry of the flipper just doesn’t allow this fix to be very good. Plus, my NOS parts came with NOS factory rust in non-critical locations. The original flippers work pretty well without the fix.anyway. I will probably use these kits up and switch back to the original-issue parts once I exhaust my small supply.

Flash lamp weirdness

I chased down the flash lamp problems on my Monte Carlo.

The flash lamps next to the roulette wheel were locked on. I found a out-of-spec transistor on the driver board.  The under-playfield transistor (MJ2955) tested fine once the driver board was disconnected, so I just left it.

The other one was weirder. The “left dome” flashers did not work. Lamps themselves were fine. The transistors tested okay, and there was voltage at the lamp socket, but grounding the lamp socket did not cause the lamps to light.

I found that the two lugs of the lamp socket were shorted together. Apparently the resistor in circuit that steps down the voltage is good enough to protect the transistors from failing, or I just got lucky.

I might have caught this sooner if I’d noticed that the last person to re-rubber the game had looped rubber around 89 sockets rather than reading the manual for the correct rubber ring sizes.

My Monte Carlo

In March 2013, I picked up a Monte Carlo. Nominally, it was working. But it needs some work. Here’s a rundown so far.

The head glass was cracked in two pieces, held together by the trim — just barely. I got a new one through a friend who got it cheap, but we got it cut just a little too small.

Next, the mezzanine board on the MPU was cracked.  All System 80B games self destruct because of this damn board.  Because it is single-sided, and all single-sided boards on a pinball get cracked header pins, it causes the computer to become unreliable, if it boots at all.  Someone had “fixed” mine by jamming packing peanuts in it.  I fixed it by desoldering it, removing solder, adding fresh solder, and putting it back.

Fortunately, this game shipped with one of the cordless phone-style batteries and had not leaked.  Unfortunately I got a little ahead of myself when removing it and I lifted a trace.  I replaced it with a memory cap and did an OK job, but the lifted trace still annoys me.  It was otherwise a perfect MPU.

The right flipper was weak, so I couldn’t get multiball started, because I couldn’t make the Firepower top-capture shot.  But worst of all, the roulette wheel had dirty switches, which meant that there was no way to win roulette and the game would have to time-out every roulette spin.  Terrible!

I did immediately start looking for a topper, and found one locally. I cleaned and reinstalled it and it looks great, or at least as good as that topper ever looked.

Around this time, I bought my Spring Break and got sidetracked, since I’d never even played Spring Break.

After almost a year, I’m back trying to play Monte Carlo. First order of business was the roulette wheel.

The spinning bit is held on with a set screw that might be accessible without removing the assembly. Removing the whole assembly is a good idea to clean it. But if you remove the six screws holding the window on, then take the set screw out, you can probably lift the wheel out.

The wheel has twelve switches and I guarantee they’re all dirty.  I cleaned them with whatever scrap of paper was in my pocket and now it works pretty well.

I also put new foam washers to hold the window on. Now, the window is much closer to level with the playfield.

Now, I went to play it, and the game wouldn’t kick out the third ball to start multiball. I noticed while in test mode (testing the wheel) that switch 42 was stuck closed. The manual says that’s the trough. How can the trough have only one switch? I have no idea, but that’s all it has. On that one switch, the backing blade was bent against the playfield-touching blade.  I adjusted it, and now I have multiball.

Still to go:

  • Right flipper too weak.  Left flipper too, perhaps, but we’ll see.
  • A couple light sockets are bad. Target #5 is burned out, and the bulb is the most inaccessible light I’ve ever seen on a playfield.
  • +5V filter cap hack on transformer panel should be cleaned up
  • add redundant +5V/ground lines on MPU-driver cable
  • blown transistor for the flash lamp on the roulette wheel; lamps are missing from their sockets because they’re locked on (and burned the playfield!)