Hello,

I'm posting this inquiry to the public because I've faced a perplexing issue with my PC and I'm having problems figuring out the solution on my own. I have a HP m7850n that I've been modifying over last 3 years. Approximately 9 months ago I purchased XFX 8800GT and I was very pleased with it until June this year. In June I went on a business trip to Sweden for couple of weeks. During my time there my wife called to inform me that a violent storm struck the area and an electrical surge fried our ADSL router as well as computer's PSU (the PC was off during the storm). When I got back I removed the damaged PSU and replaced it with a backup, however it was much weaker and I had to replace the 8800GT with the stock 7300 LE that came with the desktop. Everything seemed in order so the next day I went out and bought Thermaltake 550W PSU. I hooked all the components up including the 8800GT and was immediately confronted with a BSOD with a 0.0000007E error. The issue was easily fixed with a driver purge and reinstall in safe mode. After finally booting up to Win XP I fired up Crysis Warhead just to find out that after about 5 minutes the game would freeze with some artifacts and looping sound. Same thing happened in STALKER Clear Sky as well as Settlers 6. However WoW runs fine. After trying out several sets of drivers I decided to test a different card I replaced 8800GT with a brand new PNY 9800GT 1024MB and right off the bat the card started to shut down and monitor displayed a message "No sync dedected". This would happen in games, win desktop, and even during boot up. I concluded that my 8800GT wasn't faulty and it must be the PSU hence I replaced it with Antec Earthwatts 650W. Surprisingly the same issues persisted with 9800GT and 8800GT. Now I'm running out of ideas and I'm wondering if the motherboard may be malfunctioning. If I am to replace the Mobo I'll do it along with the CPU becaause I would like to switch to Intel. My specs are:

AMD Athlon 64 X2 Dual Core 4600+
2GB RAM
XFX 8800GT/PNY 9800GT
Antec Earthwatts 650W
Mobo (unfortunately I can't find out what model or what brand it is but I saw nForce printed on some of the chipsets so I'm assuming its a nForce mobo.)
Western Digital 320GB

All right will run the memtest. Yes I am aware of that, I bought it mainly for the testing purposes because I would not believe that 8800GT would fail just after 9 months, going to return it as soon as this is solved. The symptoms that 9800GT produced are even more puzzling though, I think this card might be actually faulty.