Okay, here's my problem. I recently did some upgrades to my 3-yr-old Sony VGC-RB43 computer. I replaced the stock PSU with an Antec Earthwatts 650w PSU (22A,22A,25A on 12v I believe), I added two more 512MB RAM modules (PNY PC3200 DDR 400/333/266 mhz) to bring it up to a total of 2GB, and I added a PNY GeForce 7900 GS graphics card (PCI-e). Now, my computer will randomly freeze up completely, usually without even giving me a blue screen with the error message. I did get a BSoD one time since this has been going on, but my roomate has since thrown away the paper that I had it written down on. Its kinda strange the way it doesnt put up a BSoD or anything, it just freezes up completely. Usually there is some weird artifacting that happens on the screen, most commonly a horizontal bar that sometimes moves a little, but other than that the screen just completely locks up. I also lose power to any USB peripherals. I'm thinking that I may have a bad RAM chip or something, although it seems more like a power issue. The GPU I believe only needs 20A dedicated to it, and everything else is stock (plus the two RAM chips I added) which means a P4 HT processor.
Anyone got any ideas on how I can fix this?