Author Topic: williams Pharaoh reset problems  (Read 1482 times)

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Offline beaky

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Re: williams Pharaoh reset problems
« on: June 21, 2014, 12:08:24 PM »
I put a meter on the +5 at the power supp and with each time the flippers were pressed (at around 1 second between each press) the voltage would drop .03 of a volt (5v, 4.97, 4.94, 4.91 and so on) until the machine would reset.

Hmmmm, the accumulative decrease in volts looks like the main filter cap(s?) is dodgy and not recovering/charging quick enough to feed the regulation circuitry....
I haven't had the pleasure? of working on a dog board, so i'm not familiar with whats going on around their regulation design.....

just my 2cents ;-)
MM
That does make sense marty
the weird thing was u stop pressing the flipper buttons the voltage would not go up.
The only time it would recover is when the mpu board went into reset.
I will let you know what the problem was when I sort it out:
« Last Edit: June 21, 2014, 12:14:11 PM by beaky »
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