Hey, I am totally lost on how to solve my problem. I posted this under PSU problems since I do not know what part is causing my problems. Hey everyone, new poster, longtime fan of the boards here. I was wondering if someone can answer my question. First off, the specs: AMD athlon 64 4200+ 2.2GgHz Socket 939 Hiper 580W PSU Sapphire Radeon X850XT GPU ASUS A8N32-SLi Deluxe MoBo Seagate Barracuda 7200.10 320Gb SATA HD (fried, not currently using) Hitachi Deskstar 320Gb 7200rpm SATA HD (as replacement) WD Caviar 80Gb IDE HD Corsair XMS Platinum 2Gb 184pin DDR memory Okay, here is my problem...When I originally built the computer around August last year, I had some problems that I assumed was a DOA from ASUS. The problem was no video on boot. I RMA'd both the video card and the ASUS Mobo and replaced them with the same models (it worked with the old video card and new MoBo as well). Immediately, I came across a problem with the new MoBo--it would not reset. Whenever I pressed the reset button on the case, it would freeze on the boot screen. In addition, when I turned off the power (from the case button) and turned it on later (leaving the PSU on) it would do the same thing. However, if I turned off the power to the PSU and then back on, it would boot normally. Soon after I figured this out, I had random crash/shutdown problems. I was able to narrow it down to the nVidia ethernet port. However, If I use the other Ethernet port (Marvell Yukon) it works normally so it is not a problem. Now, afetr these headaches, it is beginning to act up again. For some reason, sometimes (and now permanently) when I turn it on, there is no video. I moved the GPU around a bit in the slot, and it worked normally. For a while, I was able to get by with lightly wiggling the GPU in the PCIx16 slot during the boot and it seemed to work. One day, when I was in class, I came back to a frozen screensaver. With the numerous problems I have had before, it came as no surprise. When I booted, it could not find any boot record on the HD and I had to purchase another HD. I nearly lost all my data! From there, it got progressively worse--now it will not boot at all no matter how much jiggling and wiggling you do to the GPU. I decided to try some other things. I unhooked the SATA drive, loaded PCLinuxOS on a spare IDE drive and suddenly the PC started working again. I hooked the SATA drive up again...and no video on boot. So, I hooked up my SATA HD to an external enclosure/power supply, and it worked normally for a while. Now, it keeps getting worse and worse. It will not boot with the IDE nor with the SATA drives on external power (so it would just be powering the fans, MoBo, and GPU). 580W seems more than enough to power these things. I cannot figure out if it is a bad MoBo or a bad PSU, I'd like to find out before I have to spend hundreds, and perhaps before I tear the rest of my hair out over it. I've rebuilt this thing more times than I can count to ensure everything connected and hooked up right. Voltage readings from the ASUS diagnostic software is normal. Also, once I get it to work, it used to stay on for however long I kept the computer on for. The last time I got it to work, it loaded Windows normally for about 5 mins, then froze and shut down a few seconds later. I've tried everything I can think of while it still worked, every diagnostic looking for some kind of error and found nothing. Now it is a very expensive and frustrating paperweight! I should also add I've reflashed to the most current BIOS and checked some unsuspecting things like my surge protector capacity and room's electricals. The GPU fan normally spins at full speed and then slows after POST, and the Keyboard lights up and blinks (LED). Now, the GPU fan stays full with no video, the monitor detects nothing, but the keyboard still blinks, etc. like a normal boot. I've switched the monitor input/GPU output, etc. with no results. I'm baffled!! I thought it could be the GPU but I replaced it early on when the same problem occurred. I do not know if this is MoBo or PSU or GPU or something else! I figure if anyone can help me it'd be someone from these boards Thanks!