One possible problem may be the temperature sensors and/or overheating. When you lock up, are you running intensive tasks, or does it just happen at random? You've obviously opened it up; is there a lot of dust on the inside of the G5 or in the power supply? Have you looked at your system logs to see if there might be a clue in there? I'd also try running a temperature monitoring program and see if temperatures are getting unusually high in the processors. Just a few suggestions... Eric On Sep 22, 2008, at 2:47 PM, Steve Adams wrote: > I had that problem with a dual processor G4. Problem kept getting > worse until I couldn't run the computer for than 15 minutes before > it would lock up. I bought new (and upgraded) processors and the > problem has not reappeared since then. That was a year ago. > > Steve Adams > > > > > > > > > On Sep 22, 2008, at 12:54 PM, Andrew J. Yon III wrote: > >> I know this is probably old news to some of you , but it is driving >> me nuts trying to figure it out. Other than replacing one piece at >> a tim, which will be too expensive, does anyone know what is most >> likely the problem ? >> >> Background information : >> >> • I have run the Apple Service Diagnostics Disk for this machine - >> All tests pass Green. >> • I have run the Apple Hardware Test Disk for this machine - All >> tests pass Green. >> • I have run the TechTools Pro 4.6.1 Disk for this machine - All >> tests pass Green. >> • I have replaced the RAM. >> • I have replaced the Hard Drive. >> • I have reinstalled the operating system (originally Tiger), then >> tried and now is 10.5.5. >> >> and yet, at random ( times vary, sometimes minutes, hours, and even >> days), it will freeze the cursor and then a minute or two later, >> the fans all will start ramping up until they are running full blast. >> >> It is still set up in stock configuration, as it came from the >> factory, other than the operating system and the RAM. >> >> As it stands now : >> >> G5 june 2004 DP 2.0 >> 3.5 GB RAM >> two 160 GB hard drives (SATA) >> no pci cards >> 5200 video card 64 MB >> >> >> Any ideas how I can determine what the problem is other than parts >> swapping ? >> >> This machine runs perfect while it is running until it freezes. >> >> >> Andy3_______________________________________________ >> G5 mailing list >> G5 at listserver.themacintoshguy.com >> http://listserver.themacintoshguy.com/mailman/listinfo/g5 > > _______________________________________________ > G5 mailing list > G5 at listserver.themacintoshguy.com > http://listserver.themacintoshguy.com/mailman/listinfo/g5