Williams System 9

LyonsArcade

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Some guy brought me a williams system 9, space shuttle board that he wants me to try and fix. He tells me that the thing worked fine in his game for about a year, then stopped. So he mailed the board off to be repaired, and some place "in texas" he said mailed it back and said it couldn't be repaired because of all the battery damage.

So reluctantly I told the guy I'd look at it, although I can't promise anything. I don't even have a pin to test it in, so I'm going to have to just bench test some stuff.

Right away his story is b.s., I don't know if he did it, or the place 'in texas' did it, but this board hasn't worked recently. First of all, just glancing at it, there's no rom chips. Also, the cpu chip is missing.

Upon further inspection, the cpu chip that's in the 'sound' cpu socket is an 6821... which is a PIA as I understand it, and the schematics I found online say the chip is supposed to be an 6802 or 6808. They didn't even remove the 6821 from another place on the board, because the other pia's aren't socketed. Somebody went through the trouble of finding the wrong damn chip to put in the socket....

What the hell is going on with this board? Also there's not a trace of battery damage. I can't decide if the guy just made the whole story up, or if the place he sent it to really pulled a number on him. Even that doesn't make sense though, because the board hasn't been hacked or anything, it looks repairable.

Another interesting thing, every system 9 board I've seen has sand resistors in the corner for the lamps. This one, has half of them sand resistors, the other are more traditional resistors that are TOAST... it almost looks like somebody removed the sand resistors, then put the wrong ones in and let them eventually get so hot they scorched the board.

I'm going to order some of the right chips for him and burn a couple roms and test the transistors out on the board, maybe we'll get lucky.
 
Another interesting thing, every system 9 board I've seen has sand resistors in the corner for the lamps. This one, has half of them sand resistors, the other are more traditional resistors that are TOAST... it almost looks like somebody removed the sand resistors, then put the wrong ones in and let them eventually get so hot they scorched the board.

I'd guess those resistors went (physical damage during a previous repair?) and the guy doing the 'repair' didn't have appropriate parts, so he just shoved in something with the right ohm value. Probably didn't understand what the wattage rating meant, so he ignored it.
 
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