Sleep & Shutdown Problem

[Ping Pong]

Greetings, Thanks for your time and help. G4 MDD dual. Was working fine. Disconnected and moved to another room. Now powers up, runs about 10 minutes and then, goes to sleep. Tap keyboard and it wakes up but, immediately goes right back to sleep.

Did the PMU/CUDA, did the discharge (power button), battery is okay, Power supply fans are running, all other fans are running, de-fragged, new system install and it still does it. Checked for "stuck" power on button.

Note: When G4 is warmed up and booted from install CD and in the middle of the install Mac "shuts down!" Had to wait for it to be cold and then have approximately a 10 minute window to boot from CD and get through the new installation before something heats up and causes the entire computer to shut down. Once new system is installed goes back to it's "sleep problem" after 10 minutes of running.

So......it ain't the software. Can smell faint "burnt odor" in the vicinity of the power supply. While cold the computer works just fine.

I suspect it is the power supply but want to be sure before spending the dollars.

Any ideas???

Ping

 

[Makosuke]

Sounds like your assumptions are correct in that it's almost certainly heat (or rather overheat) related.

The question is whether what you're smelling is, in fact, the power supply, and that's what's causing the shutdown, or if the component that's actually overheating is the CPU. Actually, I'm not even sure how many thermal sensors the MDD G4s have--I know at least CPU, but maybe there are others, too. (And that it's going to sleep, not just dying, does point to it being something that the OS is monitoring.) Ruling out other thermal problems before springing for a new power supply might be a good idea.

If you haven't already, you should download one of the many temperature/fan monitoring utilities and see what temperatures are being reported and what's the hottest when it shuts down.

On the same note, don't those have heat-reactive fans? Are the fans running at full blast and/or abnormally high for the conditions before it shuts down? I'm assuming you'd have noticed if they were, so if they're normal that'd seem to point the finger at the power supply.

The only other thing I can think of is that the heatsink would have gotten jarred loose, but again that would probably lead to the fans running really fast.