Client called for repair on Junkyard, no boot situation. Checked voltages on driver board, and find that 5V is missing (no LED 101, only 1.4V DC at TP101.
I check the incoming A/C voltage at J129 and find 9.63V A/C, so I'm satisfied that it's a board level issue. I replace the voltage regulator LM317 at Q1 after checking the resistance of R1 and get 749Ohms, and R1 and get 242.6 Ohms. Figure that's close enough to ensure that we're getting at least real close to 5V from the Regulator. No dice, still no LED, and nothing higher than 1.4 at TP 101. I check and replace (even though they were OK) D7 through D10 with new components. Still no change. The only thing left is c9, and while I will replace that, when I get the part in, I can't see what's left if this doesn't solve the problem. Is there something I'm missing here? What else is left? Oh, I forgot to mention, I checked fuse F105, it's fine, continuity along the circuit is fine. I reflowed ALL the associated header pins with new solder, including the fuse holder legs, J 129, J 136 and 137, and obviously all the new components.
Any suggestions on where to turn next would be greatly appreciated, as I don't expect this will turn out to be a bad cap. P.S. this board was tested in a known working WPC-95 game, and the results are exactly the same, so it is definitely a driver board issue as far as I understand it.
Thanks