All right, I'm having a problem that has me stumped, and I can't think of a cheap way to troubleshoot... so here I am. Now, as you can tell from the title of this thread, my computer powers off right after I turn it on. Sometimes it will boot up Windows just fine, only to have it turn off automatically after 10 minutes or so... but 9 outta 10 times, the system won't even stay on for more than a second. Naturally, I thought it was a shoddy PSU... so I swapped it out with a PSU from my other machine... same problem. (?!) Next, I tried unplugging each of my drives/HDs, one by one... maybe they were causing the prob somehow? Nope... Now I was able to get into my BIOs briefly before my last crash. I checked my PC Health settings, and everything checks out. My fans are spinning properly and my CPU seems to be staying at a cool 30 degrees C. Now I have had a fan make some noise once in a while, but not enough to get me worried. (No, I don't know which fan) When I power on, all fans spin nicely... then the system just shuts off... usually before POST. BAH! On the rare occasions it lets me into Windows, my logs show no problems... not even an "Unexpected Shutdown" error... Windows doesn't even try to check the disk for errors during boot... you know, like it normally does after an improper shutdown. Ok, here's my specs: Gigabyte MB with a AMD 64 3200+ CPU 1 gig o' RAM (2 matching Kingston 512s) Seagate 120gig SATA HD GForce FX 5700 video SB Audigy2 Platnium sound The system was assembled by me in Oct. 2004... it hasn't given me any trouble until now. I keep it dust free, in and out... no dust on the inside that I can see... and I haven't made any hardware upgrades in months. I'm out of ideas.