I am seeing something across multiple classic Bally pins that makes me think it is an actual bug in the firmware. It has to do with the LATCH signals for the displays. Specifically the Credit/Match/Ball (CMB) display.
Tag Archives: bally
Dead Gorf
So I found a dead Gorf on Craigslist. It was an older ad, but was still available when I inquired. Dude I picked it up from had done some pretty impressive restorations on some other games.
Anyway – it was dead alright. Shows a blank screen that looked overly blue due to how the monitor was adjusted, no starfield was visible. Slid the test switch over and power-cycled, but this made no difference either.
The previous owner had mentioned that he had done some work on it. I saw some of his other previous work on other boards of his and while not perfect (some cold joints, or not enough solder in some places leaving “pits”), it was not horrible and definitely no worse than what I was doing when I started out.
Anyhoo, starting with the power PCB – the previous owner said he had already replaced the caps, but I wanted a second look at it, JIC. On the solder side of the board, some larger traces has been lifted off the board during some previous repair work (I do not think it was his, maybe someone before him?).
It looked like the someone used a serious soldering gun to do the work, because there were scorch marks on the board(!) and flux was all over the older work too. Continuity was where it was supposed to be, so I guess that while it was ugly, it worked. Continue reading Dead Gorf
Galaxian – “Dead”
Purchased described as “dead”. Started by creating a JAMMA adapter (I hate creating adapters, it is tedious work). Well, the description was correct – she is dead alright: screen has static garbage and required some tweaking to sync correctly on my test bench monitor.
Watchdog is barking, disabling it has no effect on the screen’s contents. Board already had some previous work done in it, solder-side contains more than 20 jumps to connect some RAMs back onto the bus. The Parts side shows the missing/removed/blown traces being jumped.
Started by checking the daughterboard, seems OK. Next I remove, socket and replace the 74LS245s on the board because word has it that they tend to be the cause of most problems, the Galaxian Trouble Shooting Logic Board manuals lists similar symptoms connected to those chips, and the Fluke 9010 troubleshooter says that the address lines are tied. Other than that, I cannot come up with a good way to check them! 🙂
Gotta wait for some replacement sockets and chips to come in…