Crucial Balistic ddr2 memory, replaced cpu 2 times new ultrax4 850 watt power supply tested power suppl with a Dr. Power II tester (tested good)Talked to crucial and did on board testing( put 1 stick in slot 1 and tried to boot NG moved to slot 2 then to slot3 then to slot 4 No boot then did the same with stick 2 then 3 and finally 4 no Boot CRUCIAL SAID 1 STIK BAD POSSIBLE 2 BAD NOT REALLY 3 BAD ALMOST IMPOSSIBLE ALL 4 NO WAY BOUGHT SOME STANDARD DDR2 NO DIFFERENCE Changed Video card and SCSI card with new ones and took out Sound Blaster No BOOT CHANGED CPU STILL DEAD CALLED Asus their answer is warranty is only good 1 YEAR FROM MANUFACTURE DATE NOT PURCHASE DATE