Tag Archives: bally

Bally Star Trek repairs, part 1

I got a Bally Star Trek back in November 2014. I knew the computer would be corroded, so I pulled it and removed the battery. I didn’t leave myself enough lead and I don’t think I’ll ever get both terminals out. There are quite a few missing traces and damage. I hurt my hands trying to get the damage out.

I picked up another board from a sale on RGP, also from a Star Trek, that is a better candidate. It only had a little corrosion, but it doesn’t boot.

As a stopgap I picked up an Alltek CPU. I want a -35 CPU for some reason, so I’ll probably still fix the clean one when I have a chance to get some help.

When checking out the head, I found my driver board (one of the nice Stern ones with really elaborate silkscreening) was missing two transistors. I replaced them. While I had the board out, I removed the filter caps for the high voltage and the +5V. The +5V cap was bulging—so its days were numbered anyway, as if being 34 years old wasn’t enough reason to replace it.

Power cord was missing ground prong and was a little damaged, so I replaced it.

My lack of skill at drilling out the lock left lots of metal shavings in the game, and since the lock is over the rectifier/transformer assembly, I pulled it and vacuumed out the head.

The sound board was removed to make it easier to get the transformer out, so I re-capped it. I re-installed it and the game had a loud hum tied to the number of lights on. I removed the sound board a second time, and discovered about a third of the header pins had obvious cracked solder joints. I resoldered them and plugged the board in and it worked great. Then I screwed it down and the hum was back. I’m guessing I have a floating ground somewhere. Given the obvious age of the header pins, that is not surprising.

I was missing a full row and a full column of switches, including the outhole and the saucer. (When I bought the game, the seller told me that it didn’t work. He didn’t know about any of the other problems.) I re-pinned the connector to the MPU and I have most of the switches. I suspect cleaning will make the rest work.

So, it plays. Just not well.

After I wrote this, the draft sat around for years. So did the game. That’s the problem with old games: they are great for storage. Around 2017 I borrowed the SDU board. It sat outside the cabinet for three years until I got around to re-installing it.

In 2020 at the beginning of the pandemic, I got an offer for the game as-is. Since I had too many projects, I sold it, and a CPR playfield. And I finally have some space for the Eight Ball Deluxe project.

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Spy Hunter Fixes (or, I can’t follow simple directions from anyone)

A few years (!) ago I bought a Spy Hunter. It played blind.

I got this game as a sweetheart deal, and I got a great price because it wasn’t working. It belonged to a friend who used it for party rentals. I knew it had been well maintained. Must be a loose wire or a fuse or something.

I talked to Chris, who said that if I pulled the boards apart, everything would work until the game got moved. Well that sounded pretty annoying. So, as I am wont to do, I bought some parts—in this case, a set of new interconnect cables—and put them in the cash box for some other day.

Well, that day was in late 2019, when I conned GMike and I into taking a look at it. Still no video, and no obvious reason for no video. So we replaced the interconnect cables. This is a pretty large pain in the ass, because the MCR III system is such a convolution. Power comes in one end of the board stack, I/O comes in the other end, and all the spring tension on the connectors is so tight, they’re nearly impossible to take apart.

GMike and I got the boards apart on the dining room table, cables replaced, back together—same thing. I texted the previous owner and got the scope out and handed it to Mike, who confirmed the video pins weren’t videoing. I have a pattern generator for the monitor, which proved it was OK. The text conversation went back and forth a few times until I realized the video signals weren’t connected to the CPU, but to the Super Sound I/O board which, for some reason, has a connector with exactly the same connector as the CPU.

So we moved the connector over and played some Spy Hunter.

Next problem: bad power switch. I think it had just mechanically failed and wouldn’t stay off. Unfortunately we had to change the QD connectors from .25 to .187, but they work just as well.

Last problem: no saved settings. There are two types of difficulty setting in Spy Hunter. One is DIP switches and controls how long the “unlimited cars” time is. The other is in software, and coincidentally, also saves high scores and bookkeeping.

The battery had long since been replaced with a supercapacitor. But when the power was shut off, whether or not the card rack was connected to the power supply, the available voltage dropped to nothing quickly. So, GMike put a new cap in it. That would at least hold voltage with the power off. But with the boards connected, voltage would drop.

Chris suggested replacing the 6116 on the CPU, or the capacitor and diode on the power supply related to the battery. I had the cap and diode, so I replaced them. I would have done the 6116, but it’s so difficult to get the card rack out, I put it off. I got some 6116s from Chris on a visit to his shop, and actually ordered an NVRAM so that I’d only have to go at this once.

Tonight, though, rather than put the NVRAM in, I wanted to get the 6116 to work. It’s so difficult to get the ribbon cables off, I stopped trying, and learned to work with the boards connected (very carefully). Actually, the Spy Hunter is in the garage, and the available low-static workspace I had was a pinball machine in the house, so I just took it inside. Where it’s warm.

I got the stack apart and couldn’t find the 6116 on the CPU board. So I looked around and saw that it’s actually on the video board. I put in a new chip, and no change. (OK, one change: the video connector is so hard to get on, I missed pins and corrupted the video. Other than my heart breaking that I just broke the game, no problem.)

So I put the NVRAM in. It barely fit in the stack. Plugged it back in, and the sprites were either missing entirely or corrupt. Uhoh. Had I changed the wrong 6116? Yep. The correct 6116 to change is on the CPU board, at 5G, and this was documented by the vendor. I had missed it because the original chip had a weird part number. So, on my third reassembly of the day, I put the right chip in and reinstalled, and things appear to be working!

(So I can’t really say that the NVRAM didn’t fit. I mean, if you put it in the wrong place, it doesn’t fit. That isn’t helpful. However, the NVRAM will not work as video RAM. That’s also not helpful but is something of a fun fact. I guess.)

I finally increased the difficulty from default 3 up to maximum 9. It’s a more interesting game. At 3, there are a lot of times where there are no spy cars to attack. At 9, there are spies almost all the time. It’s great.

I re-checked the voltage, and with the power off, it stayed around 4.80, a big change from the various broken parts. So far, the cap appears to be working.

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I bought a (Bally) Star Trek; or, how not to drill a lock

A friend posted a link to a $400 Bally Star Trek on Craigslist. It was clearly bombed out, but I was looking for a restoration candidate. I went for it.

The seller said he didn’t have the head key. This meant two things: first, it was going to take a  big vehicle to move it back to my house. Second, the computer was going to be corroded. But the game was mostly working, how bad could it be?

I a U-Haul van, a little Ford Econoline, at the place near my house, and headed to the seller’s place. I got there around 5 and after some smalltalk, I paid and then started figuring out how to get the game in the van. I have skates so it wasn’t too bad. I got the front legs off and we got the front of the game onto the van; then, the back legs off, and slid the game right into the door latch of the van.

That’s right, a classic solid state Bally game won’t fit in an Econoline van with the head on.

Fortunately, I was somewhat prepared for this eventuality and had my drill and a bunch of bits. But I didn’t think carefully about how the backbox works and spent two hours trying to open a door instead of just lifting the glass out.

I finally lifted the glass out in the relative dark and got the game home in three pieces: head, cabinet, and glass, which I won’t put back in until I have a proper lift channel on it.

Anyway, I bought the game in early November and am just starting to shop it. Eventually I’d like to restore it, but this is at the end of a long list of projects.

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