


So my question to the community and anyone from Apple watching this thread. I've even tried removing all peripherals. Still, the machine will only startup if the power cord (or UPS) is unplugged (all power disconnected) after sleeping or shutdown. I've tried cleaning the machine (G4 Quicksilver Dual), Taking RAM out and re-seating it. #2 which is what I'm trying to solve for my father, seems to be either power supply related or something to do with the system not properly shutting down. Flashing light/logic board flashing red light. Power light illuminates when pressed but machine doesn't start/do anythingģ. Flashing light and some fan action but no bootĢ. I see different issues in the thread so far.ġ. Has anyone found any solutions that fixed the issue? The computer can be stopped by pressing long time on the power button. And only got back to : fans up, light when button pressed, drives are checked by BIOS, but nothing boot. Then reset PMU the first (and normal) way. This lead me to a totally non fonctional computer : no light no fan nothing. I also tried the method for those boards without reset button : 10 minutes without power nor battery, replace battery, et voilà. As it has a PMU reset button, the procedure should be : pull the power cord off, evenutally take back the battery, replace it, push the reset button, and wait at least 10" before pluggin the power back. Unfortunaltely, the docs available are never about this peculiar type of G4, always for former ones, so I cannot really be sure of the right way to reset it's PMU. I've juste got my neighboor's MDD G4 this afternoon with the exact same symptoms.Īs I had already seen this with a Dual G5, even if it's not the same box, I really think it's a PMU related problem (or maybe SMU if it already has one ?). how we're finding ourselves several in the same case ! I'd be willing to take the gamble that it is the power switch board and pay $40 to replace it if it sounds like this might be it. I've previously had to replace the circuit board behind the power button on a older blue and white G3 machine, but I don't remember the symptoms. I've tried removing the battery, resetting the PMU and leaving it for 30 minutes, but still no luck. Subsequent presses of the power button the button light will not light, but the fans will move briefly and the light on the logic board will flash.

The symptoms are that if I plug it into the wall, then press the power button, I will see the light on the power button as well as see the fans spin for a moment as well as a red light flash on the logic board itself but that is it. We had a power outage recently, and afterwards my PM MDD G4 won't turn on.
