Well, I removed one SIMM and it now works. So I moved them around and they both work in one slot but not the other. So, the problem could be the power supply or on the motherboard. I don't know how to determine which. And I haven't went out and bought another power supply since mine is rated at 585W. A replacement would be about $100, a bit much for an experiment. -- Don't stop where the ink does. Shawn