I have a powermac g5 dual 1.8 that freezes after being used for a while and will freeze constantly afterwards if you try to use it after it freezes sometimes not even getting past the gong sound. I am leaning towards a heat problem but it doesn't seem to be related to the cpus. I am thinking maybe gpu related or hopefully not the logicboard. I have reinstalled the OS and the problem still exists. Anyone have any suggestions on fixes for this machine. I have also swapped the memory with other sticks i have laying around, only used the original apple memory and used only the upgraded memory. Makes not difference so its not memory related.