Ok changed the Power supply out, put a UPS in front of that and ran SiSandra Pro tests on it 10 times in a row and everything passed this last weekend...last night about 8pm it did it again, popped the side panel off and the Northbridge fan was not turning (good thing I hardwired the cpu fan ) ...push the power button and that fan came on but no go....powered down and back on and she's good as new again. OHH and I put another stick (just one this time) of Crucial256 2100 in when I changed the PS out..unless I keep getting bad sticks then I'll rule that out. Got 3 sticks of ram now...too bad only 2 slots on mobo ....guess I either live with it ...replace it...or something, got Geforce3 coming wednesday so I can at least rule that out!