Pinbot
Williams, 1986You're currently viewing posts by Pinsider brijam.
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I have two crossed columns on my Pinbot, 3 & 4. Each lamp on column 3 is coming on when the corresponding lamp on 4 is lit and vice versa, e.g. Uranus and Yellow 2 both coming on when either is lit.
I measured IJ7 and got these values:
1: 5.1v
2: 5.2v
3: 5.2v
4: 5.1v
6: 7.8v
7: 5.7v
8: 11.2v
9: 5.1v
So I think that means that something is wrong on the board, but I just don't know how to find out what it is. Help!
Quoted from CadillacMusic:Well, it means either something is wrong on the board, or your column wires are shorted together physically. Were you doing anything to this machine other than playing it? Have you looked for any wiring that might be dripped on or smushed? My off the cuff guess is that it's cpu related, but wiring is almost just as likely. If it is indeed on the board, you're probably looking at a bad U53, but if you were doing any repair in that area, it's very easy solder splash two pins together as well. Do you have a multimeter and know how to use it?
I don't think it's the wiring. The machine was recently transported, and I removed the board to have someone fix a bad transistor. The problem cropped up after that.
I do have a multimeter and I do know how to use it. I just don't know what to check.
Quoted from CadillacMusic:Well, unplug the lamp driver plug 1J7. Then measure to see if you have continuity between pin 3 and 4. That won't rule out a board problem, but if you have continuity you know for sure it is a problem with the board, most likely a drip.
Thanks, that was exactly what I needed. Turns out one of the bayonet bases was touching something it shouldn't have been.
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Bethlehem, PA