Category: Arcade Tech and Repair
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+43 Volt Error on a Alltek Systems Replacement MPU Board
So I was helping another collector in the area try to get a Bally Star Trek Pinball running. It had a Alltek MPU replacement board it in that would start to boot but then stop with 5 diagnostic flashes which indicate a problem with the +43v supply. However, when metered at the test point, the…
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New Language and Compiler for the Fluke 9010A
I have always been fascinated with the older Fluke 9010A microprocessor troubleshooter. I have owned a few through the years and my current bench one has the serial port on it for transferring programs and data between the unit and a PC. However, I never found its programming language (usually referred to as 9LC, the…
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Frogger Problems
So I visited the arcade of someone I have come to know and while taking a look around and playing a few games, I stumbled across this screen on a Frogger: Not exactly playable, if you catch my drift. Went over the usual stuff, power, reseating, etc. Voltage was a little low, and the power…
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Fuse Voltage Ratings
Everyone knows what the amperage rating on a fuse is for and what it means. But do you know what the voltage rating is for? Maybe not what you think. Quite a few people think that the voltage rating of a fuse indicates the voltage that the fuse will blow (or break) at, like what…
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Galaga/Bosconian RAM Tip
Galaga uses 4-bit RAMs. This means that in order to handle 8-bit data, it needs to group RAMs in sets of 2 – one for the lower 4 bits, and the other for the higher 4 bits. When Galaga detects a RAM error during the self-test, it does not show the location of the failed…
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Dead Vanguard Board
So I came across a dead Vanguard that was for sale. Described as only producing a boom sound effect and then a rumbling/static-y noise. Bought the thing home along with 1.5 spare boards and did the usual checks: Power, Sockets (reseat), etc. Logic probe on the CPU indicated that it was briefly running and then…
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Quick Fluke 9010 Tip
If you use the Learn function on a board, and it seems to ignore an certain part of the memory map that you know for sure is a certain type (e.g a section of the memory map allocated to RAM), run the appropriate test on that area. Bet it will detect a problem with it.…
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Williams Hardware, Switchers and CMOS
So this keeps coming up a few times a year, almost like people completely forget about how to use Google every now and then. Someone has a Williams 6809 hardware game like Defender, Stargate, Joust, etc. They install a switcher instead of repairing the existing linear supply (which is OK, people have their reasons), and…
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Watchdogging and Corrupted Centipede (Bad POKEY)
Got to work on a busted Centipede that booted to a white background screen that briefly showed the start of the attract mode (things drawn in green or purple) before crashing, watchdogging and doing it all over again. Test mode would do the same thing as well. Disabling the watchdog (by grounding the WDDIS test…
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Words to Watch Out For When Buying Arcade Games or Pinball Machines
I have learned through many years of posts, sales, people, auctions, and similar experiences that there are certain words and phrases that you need to watch out for when buying games, boards, etc. Untested The first one, and it is a biggie – UNTESTED. Here is the truth: if dealing with a whole game, and it…