This… Is my BOOMSTICK!

I was talking to a guy I do some repair work for and he mentioned he had some pinball machines he was selling… A week passed, and I went back to his place and came back with this:

The exterior of the cabinet isn’t too much to look at. It’s flaking terribly and just looks really bad. Like the plywood is separating or something, I haven’t really seen anything quite like it…

The rest of the game however, is immaculate.

Like I seriously cannot believe this is an almost 30 year old machine.

It plays wonderfully, and looks and feels like it barely has any wear on it. I can only assume it saw very, very little time on location.

Both sides of the playfield are in excellent shape, little sign it’s ever been touched. There’s next to no wear of the art anywhere, and only a few plastics have any damage. Inexplicably about a quarter of the lamps have been replaced with modern LEDs, which is a bit baffling.

The boardset is all numbers matching, and shows no sign of damage or repair. No acid damage either. The first thing I did when I got it home was pull those batteries, cause I definitely don’t want that to change…

I don’t believe it ever even had the target decals installed.

It’ll get fully cleaned, a new rubber kit, and either the LEDs replaced with incandescents, or the LED conversion completed, I’m not quite sure yet… Once all that’s done I’ll probably rotate it in in place Eventually I’d like to pick up a set of stencils and redo the exterior cabinet art, but that’ll have to wait til I have a decent environment to spray in.

Sorcerer! You Are Done, Mortal.

It turns out the issue with the outhole kicker solenoid wasn’t due to chips dying, it just looked that way because of the way the symptom manifested, and the way I was diagnosing. I’d been swapping in new 7408 chips, and that would let the solenoid work properly for a couple games, before it would go back to locking on.

Last week I ordered a logic probe to dig further into this problem, and once I had it in hand it took about five minutes to discover that, no, the chip was not dying. What was happening is that one of its input pins was not getting any signal, and as a result the output signal that controls the solenoid was not being provided. Using the probe I checked the trace to that input pin, and found it was showing what it ought to. Pushing on the chip socket would sometimes restore connectivity, too. The problem was just a bad connection, and the intermittent behavior I’d observed was happening because every time I swapped the chip it flexed the area around the socket, occasionally in a way that briefly restored the connection.

Whoever worked on the board last used a one piece socket, and I didn’t really want to yank the entire thing out since it was evident several jumpers were installed underneath it and I didn’t care to deal with that spaghetti unnecessarily. I ended up adding a Kynar wire jumper from input pin 1 on the chip to the next component back from it. Brought the board up on the bench and checked the chip, and its inputs and outputs for the outhole solenoid now looked good.

The lack of audio was super simple too. I found that one of the pins in the connector for the volume adjustment potentiometer had its retaining clip pushed in, allowing it to work its way out of the connector when plugged into something. It wasn’t visible at a glance but I noticed the wire move when I was reinstalling the MPU board after doing the solenoid driver repair. Fixed the loose pin, plugged everything in again, and the soundtrack is back!

Damn dirty apes!

Traded one Nintendo for another over the weekend. I drove my R-Type project and a few Playchoice 10 carts (Mario Bros and Punch Out, for those keeping count) up to Tacoma, and came back with a Donkey Kong Junior and a DK3 kit.

It’s a dedicated unit that doesn’t show any signs of ever having been converted, which is great! Unfortunately it’s also a US made DK Jr cabinet, which means it has particle board sides instead of plywood. When production was added in Redmond, WA to accommodate demand for the games in the US, some aspects of the cab design and materials were changed too, and the 1/2″ plywood used for the Japanese produced cabs was abandoned. This also means that the lovely new t-molding the previous owner installed actually isn’t wide enough, since it’s intended for the thinner plywood cabinets.

It plays, mostly… Though there’s some “slight” graphical issues that cropped up after my having moved it.

Need to go in and reseat the interconnect cables between the boards and see if that helps, they’re rather notorious for causing issues in Nintendo games.