Author Topic: Williams System 11c CPU LEDs - all 3 are out????  (Read 411 times)

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Offline judgeboz

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Re: Williams System 11c CPU LEDs - all 3 are out????
« on: November 29, 2009, 09:09:38 PM »
Thanks guys for getting onboard to help me out.

Ive done as requested here:
1. braided ground strap to TP1 (with the game off) - got 0 ohms
2. multimeter across TP1 (black lead) and TP2 (red lead) with the game on - got 5v.
3. retested the chips for 5v using TP1 for ground and a little different now:
3.1 U15 - got 5v
3.2 U26 and U27 - got 5v
3.3 U10, U38 - got 5v
3.4 but U41, U42, U51 and U54 the results varied from 2v to 5v. I forgot to mention I replaced the battery holder as the batteries were corroded and it looks like its on the legs of these chips too. It doesnt look to bad - do I use 50% vinegar and warm water mix to clean it up?