Help - PSUs keep blowing ! (Solved !) So, this is a weird one !! I've been running a Gigabye GA-P35C-DS3R with an Intel Q6600 QuadCore chip and 4GB of Corsair XMS DDR2, with an OCZ StealthXStream 600w PSU and a nVidia 8800GT for the past year or so. No problems. A month ago I bought myself a Palit 1GB Radeon HD4870 - http://www.palit.biz/main/vgapro.php?id=969 - comes complete with a custom dual-fan cooler as you can see in the pics. I fired up Left4Dead, played for an hour, and suddenly my PC clicked off and the PSU puffed out a cloud of burnt smoke from the back. I could then power up (the fans would spin, so I guess at least some of the 12v rails survived), but it wouldn't POST (not that I expected it to, with a toasted PSU ). So, I swapped out the PSU for a FSP 700W FSP700-80GLN (the specs of which matched the 600w OCZ exactly, so I suspect it may have had the same insides...). This one lasted an hour, before exactly the same thing happened - again I was playing Left4Dead at the time. Doh. At this point, there were two scenarios. Either the new video card was breaking my PSUs, or, neither PSU was upto the job and I simply needed a bigger unit. I chose the second option, and put in a Corsair TX 750w - with a single massive 12V rail. I figured that would be impossible to blow. It worked fine for over a week, including a six-hour session of Crysis and a bit of Left4Dead. ...and then tonight, it puffed out the magic smoke during Left4Dead exactly like the other two ! That's three PSUs in a month, all after I installed the HD4870. I've got four Hard Drives and a few case fans, but nothing crazy - all three PSUs should have been more than capable of driving my PC. I'm at a bit of a loss now. Could it be the 4870 ? It's my understanding that decent PSUs have protection against short-circuits etc. and a simple short wouldn't cause them to blow (ruling out a dodgy case-fan or similar) ? I've read this thread with interest - http://forums.techpowerup.com/showthread.php?t=66763 - it seems to suggest that the VRMs can pull massive ampage if they aren't cooling properly ... could my card have this problem, and hence kill PSUs ?