Booting Temperature Issue

[Moptop]

My mac: iMac G5, 17"

Issue: If the computer is over a certain temperature (not sure, but I'd estimate 120º), it will NOT boot up, which can be VERY annoying to me...

Any suggestions?

[DeltaMac]

I assume you don't keep your iMac in a location that gets that hot, so does your iMac actually shut itself off when it is warmed up?
The power supply on your iMac is known to be a little fragile. so you should try simply replacing the power supply. Apple may do this at no charge.
http://www.apple.com/support/imac/re...ensionprogram/

Even if you pay for the repair, the power supply is not too expensive, and is a 5-minute job to replace.

You should also check the air intake area all along the bottom edge of your iMac. Make sure that area is not plugged with debris. I see some of those models that are completely coated with lint and dust. A little vacuum brush under that area sometimes makes a big difference.

[Moptop]

I've never had it overheat and shut down, yeah its in the shade. My computer's serial number is in the range of applicable ones on the Apple page. (W850*********).

As for the power supply, it was replaced +/- 3 years ago (Along with the fans), I had a total failure of it. But I don't think it is an issue with the current one, diagnostic green light #1 inside the computer is on when it is plugged in. (Indicates power getting past the power supply, at least.).

The CPU temp hovers around 153ºF at high CPU usage, and around 142ºF at idle, is this abnormal?

[Moptop]

Bump

[eric2006]

153 is pretty normal for a CPU. 120 is a bit high for an environment though.

[DeltaMac]

Issue: If the computer is over a certain temperature (not sure, but I'd estimate 120º), it will NOT boot up, ...

You said that your iMac does not shut itself off after heating up.
Not sure if I understand your first post, then.
How does your iMac get so hot before you turn it on?
Do you shut if off _because_ you think it's getting hot? Or,
do you hear the fans kick up and then shut it off?
I guess what I am asking is - Why do you need to start your iMac, if it was already just running? If the fans come on, you should let the fans do their job to cool your system.
Do you have any software installed that will monitor the temperature and the fans.
iStat Pro widget is pretty good - http://www.islayer.com/index.php?op=item&id=7

[Moptop]

Well, for example, I was gaming, then shut it down for the night. But minutes later I realized I needed to print out a paper, and it would not boot. After a while, cooling, it did. And yes I already have that widget.

[DeltaMac]

Make sure that the cooling vents are completely clear, both the perforated area along the bottom of your iMac, and the long slot near the top in back.

My hunch, after replacing a few hundred, is that your power supply is beginning to fail.