View Full Version : Power Mac G5 won't wake from sleep + fans go insanely fast

Jul 13, 2010, 09:24 AM

This problem just started happening on my 2005 Power Mac G5 Dual 2.3Ghz Processors.

I activate sleep, and it refuses to wake up again. Then after a few minutes the fans slowly increase in speed until the computer begins to sound like an aeroplane taking off, at which point I'm forced to perform a forced shutdown.

I've resetted the PMU and it doesn't seem to have worked. It is fully up-to-date in Software Update and is running the latest version of OS X Leopard.

Thanks :)

Jul 14, 2010, 02:52 AM
Reset PRAM, but I doubt that it'll help (anyway, worth to try).
It could be few reasons of this behavior: failing graphics card, PSU or logic board. Do extended Hardware test.
Is it Early 2005 or Late 2005?
In Late 2005 you can easily test graphics card: remove it, boot your Mac (yes, it will boot w/o gfx), wait some time to system fully load. Next put machine to sleep with power button, wait some time for deep sleep, then wake it (by mouse, kbd or power btn).

Jul 14, 2010, 02:56 AM
Logic board probably. The G5 iMacs had a lot of issues, because Apple hadn't made the iMacs in that design for long enough to perfect them :(

Jul 14, 2010, 04:34 AM
Thanks for your replies, I'm running a hardware test now. One interesting thing I've just noticed however, is that System Profiler seems to think that there's '1 CPU' in the computer. It should be 2 as it is a dual-processor Mac (not dual core). Could this be it? Thanks again!! :)

Chuck Fadanoid
Jul 15, 2010, 02:16 AM
Have a look also at the error messages in the system logs. I think you'll find them in the Console app. Most of my wake from sleep issues like the one you have have been caused by USB devices behaving badly, and that would show up in the logs.

But your missing CPU does sound fishy.