Mac G4 won't Startup

[billbaty]

Hello,

After an electrical storm, even though I had my Mac G4 (733) unplugged, it would not startup. I read around on various forums and installed a new battery as well as reset the PMU. It started right up but only that once. I had to push the PMU button every time before it would startup. I just left it on for a long while but I finally shut it down again it wouldn't startup even when I would push the PMU button again.

What happens now is I push the startup button, the button lights up for a split second, I hear the chime as well as some normal internal churning then I hear the shutdown beep and the computer stops. The screen never lights up. Someone suggested that it is probably the power unit. Any help will be most appreciated.

All the best,

billbaty

 

[djackmac]

I had to push the PMU button every time before it would startup. I just left it on for a long while but I finally shut it down again it wouldn't startup even when I would push the PMU button again.

What happens now is I push the startup button, the button lights up for a split second, I hear the chime as well as some normal internal churning then I hear the shutdown beep and the computer stops. The screen never lights up. Someone suggested that it is probably the power unit.

I've had to replace plenty of PSUs in those so that's very possible. The thing that concerns me is that you consistently kept resetting the PMU which if you haven't crashed the chip yet, you probably have by now. And I'm not sure what you are talking about in regards to "shutdown beep"?

 

[billbaty]

Hello,

Thanks for replying. What should I do at this point? Replace the PSU? Or if the PMU chip is crashed, replace that first? Is it replaceable? Or is there a test to troubleshoot exactly what the problem is at this point?

All the best,

billbaty

 

[djackmac]

Really the easiest way to determine is to put in a known good PSU and go from there. You could possibly buy a power supply tester which I've never used because I usually have spare PSUs around and see if the PSU is reading the correct voltage, but I've heard they can be inaccurate.