ScoobyDoo555

Hi,

I've been asked to look at a friend of the family's G5 iMac that developed a problem.

It will power on, but then after a few seconds, powers off.

Any suggestions as to what it might be?

Thanks,

Dan

Markus

Hi Dan,
Let me guess, it'll power on, you'll hear the startup chime, then it switches itself off? I've had that on one of my G4's (which now really doesn't like to power on at all).

The first thing that springs to mind is to reset the PMU/SMU/PRAM and see if that helps. PRAM is the one I'd go for first. If that does not work, have a look at this for info on how to reset the SMU on the iMac

If that still does not work then stick a boot cd into the drive, power on the machine, hold down option key until you see the boot manager screen (if it gets that far, if not, power on and hold the C key) and select the boot cd and see if it'll boot from it. The boot manager screen will also give you an idea if the hard drive is bootable. It may well be if there is no bootable device found the mac will just power off, though not sure how true that is.

As for what else it could be, well, power supply could be failing, that is what I think is happening to one of my G4's. I do have another and I will, at some point, switch the supplies over to see if I can get it working, at least then I'll know the true cause and be able to do something about it.

ScoobyDoo555

Nice one Markus - will have a play this week and report back

dan

RichB

Not sure about G5s but old Macs had issues when the internal battery dies... *Might* be that. (Although it tended not to turn on the video at all...)