Mac G5 Power PC - If idle or asleep I have to restart

I posted this problem (below) on Monday and have reset the pram and the SMU by unplugging from the wall, as yet have not opened her up. Working with her all week the problem only occurs when she is idle, she goes to sleep and will not come back up. I put her into sleep mode myself and tried to bring her back straight away even before the fans got loud but she would not come back. So it now seems that my main problem is if the mac is idle it will not come back up without a retstart.

Been in touch with a support place who say the hard disc is failing and it needs a new hard disc, reluctant to do that but it now looks it may be the time to update.

Anyone else come across this I bought this Mac in 2005 and am told I may get £100 quid for it!


My spec is 2.3GHz Power PC G5 Mac OSX Vers 10.4.11. 4.5 GB RAM
Over the weekend I got back from a weeks holiday and powered up my Mac. On three occasions yesterday while it was left alone or in sleep mode the fans went very loud and the screen would not come back up.
The only way to stop the fans was to hold in the start button for several seconds until it powered down and restart it up again.

This has been an issue with the PowerMac G5s for years. If you have the hardware tests disc that came with it boot from it and let it run the hardware tests. Google searches reveal anything from failing Graphics cards to motherboards. Might be a sign it's time to invest in a new Mac.

It might be worth doing a clean install of the OS if you haven't already. I had a G5 that initially caused trouble booting but once booted was fine. After a while the machine started exhibiting behavior like you are explaining. Looking at the boot problems reported in verbose mode I found a couple of USB references I just could not pin down.

Since I was planning to upgrade the OS anyway and Leopard had just come out I did a clean install. The problem went away. Might not fix things in your case but can't hurt either assuming you have a backup.

If this fixes the problem initially I would reload programs via reinstall rather than from backup. Otherwise you run the risk of reintroducing whatever caused the problem. Loading data from backup should be OK.