Ich hoffe dein Englisch ist OK. Der folgende Beitrag bietet zwar keine Loesung fuer dich - es ist der Bericht eines Leidensgenossen:
"Here is an update on my random sleep problem with a PowerMac G5 2.5GHz MP, 10.4.1 Tiger (reconditioned system from the Apple Store)
I have been running Temperature Monitor and the Console log for two days now, and I have caught two Thermal Runaways on paper and have emailed them to Apple's support department for my case number. Both times the Energy Saver was set to Automatic, and all I had to do was Print something, and it gets an instant thermal spike of 104°C and it goes to sleep. The console log states "Thermal Runaway Detected: System Will Sleep".
Looking at the Console log, you can see CPU A ACS fan is supposed to be running at 1801 RPM, but it is 0 RPM (stopped). The AGP/PCI fan and the U3/Backside fans are running 100X normal, probably trying to compensate for the stopped CPU A fan. I can reproduce this problem simply by printing something with the Energy Saver set to Automatic. I'm not sure why printing something can cause a fan to stop or a thermal spike, but that's what is happening, as indicated by the temperature graph and the console log.
If you set the Energy Saver to Highest Processor, and hit print, it still thermal spikes but only to 100°C, so it does not thermal runaway or sleep (103°C is the trigger point for sleep). Setting Energy Saver down to Reduced and hit print, it does not thermal spike at all, which is where I am leaving it for now.
The printer I am using is a Canon IP3000 USB printer with the latest 2.6.2 drivers if that makes any difference.
I have had this thermal runaway problem before by just highlighting text in FileMaker or moving the mouse around in Photoshop, so this does not seem to be always printer related, but printing something is a sure way of getting it to thermal runaway, but again only if the Energy Saver is set to Automatic.
The same system is also having random Restart problems, about 50% of the restarts end up with a black screen and no restart tone, and have to be powered off/on to get it to come back to life. Apple is going to see about replacing parts on site, only after I had to buy AppleCare for it.
One interesting note about Temperature Monitor (a great program by the way), it shows the serial numbers of the CPU's. It shows that CPU A is not my original part, suggesting that it might have been replaced at some time. CPU B is the original serial number. It also shows the date of production, mine was the week of 2/26/05, so this is not that old to have one CPU replaced already."
http://www.macintouch.com/g5reader09.html
