Like the title says my pc will crash. It was happening once in awhile so i reseated everything and now...more problems. I can't play any games that require heavy load at all(BF2, CS:S, CS,...). The crash is like this... I start up the game, play for about 3-5minutes or so and its like someone pulls the plug on the pc. Blackscreen and box is off. When this happens I can't start the pc by pressing the Power Button. I need to disconnect the PSU for about 5-6seconds so the light on the mobo turns off and plug it back it. It boots up fine then but again unable to do any gaming on the box. It only happens with games..photoshop, ripping videos, normal browsing, leaving the pc on for long periods of time, works fine. Just games that seems to cause this crash. I ordered a new PSU but its going to get here friday. Since I do spend most of my time playing game instead of watching tv... I tried swapping out parts to see if I can get something to run a game for 10minutes. Used only (DIMM1&2,3&4)half of my dual channel ram, same results, pulled the plug on 2 CD drives, same result. I swapped out my gfx card for a older apg one and the pc will boot for 5seconds then turn off. Also after I reseated everything, I can no longer have both HD's hooked up. When both are connected the pc will boot up for 5seconds and shut off, just like what happened when i swapped gfx cards. Code: Abit IC-7G P4 2.8GHz 800FSB. WD 180GB 7200RPM / WD 120GB 7200RPM 1GB DDR400 (4x256MB) DualChanneled. ATI9800 128MB SB Audigy2 PSU - Macron 400W (Total Useable - 210W) I do have a PSU comming that is 500W(470W Useable) Which should be more then a enough. It going to get to my house in about 48+hours I did use a PSU calulator online and it calculated out to be more then the useable amount on my current psu. But my pc was working fine for 4months. Just recently it had these crashes once a week...after i took the pc apart and threw it back together it happens everytime. Is this a psu problem? Do psu's lose their effectivness? I don't have another PSU to swap in and try to use. Any ideas if it is not the Power Supply? Thanks in advance.