the pin was working fine. when I turned it on last night players 3 & 4 were messed up. the bottom line on each digit was out. at a closer look, I saw that the resistor at R11 is burnt. I believe it's a 10k 10% 1/2 w. I replaced it with a 10k 5% 1/2 w. so with the backglass off it, I turned it back on and the resistor started smoking. any ideas on where I should start? thanks
DISPLAY_1382 (resized).JPGUnplug player 3 and 4's displays, see if it's still smoking when you power up.
The next thing up is IC10 a 7180, hard to find IC so hopefully it's not that. If it stops smoking with the displays disconnected one of the displays is likely drawing a LOT of current to make the resistor smoke. IC9 is also a 7180 if you want to try and swap those, then R4 should smoke if it were the 7180.
See what's feeding it as well, there's 2 IC's on the schematic but I think the setup is only 1 is installed at a time IC7/IC8.... make one of those is smoked.
Those you can test with a logic probe but don't put a probe on the outputs of the 7180's you will smoke your probe (-100 volts coming out of the chip, if I'm reading the schematic correctly, combined with the +100 at the display.....)
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Smithfield, RI