Random freezes after power supply, hard drive replaced

My PC went in for repairs after a catastrophic power surge - fried the power supply and the hard-drive. Both were replaced, but since getting it back, I get random freezes independent of what applications are running. I can rule out anything bad on the hard drive as there's barely anything on the new one, the new power supply should be more than adequate, and I have run Everest to check temps to ensure it's not heat-related - temps are fine, even quite low. I never experienced freezes before the repairs were done so I think I can rule out any issues with the motherboard. Any suggestions as to what I can try next appreciated!

My spec is as follows:
Microsoft Windows XP Home Edition Service Pack 2
DualCore AMD Athlon 64 X2, 2400 MHz (12 x 200) 4600+
Motherboard: ECS KN1 SLI Extreme
Motherboard Chipset nVIDIA nForce4 SLI, AMD Hammer
System Memory 2048 MB (PC3200 DDR SDRAM)
2 X Inno3D GeForce 7900 GT (256 MB)
Temperatures:
Motherboard 35 °C (95 °F)
GPU1: GPU 49 °C (120 °F)
GPU2: GPU 47 °C (117 °F)
WDC WD5000AAKS-00TMA0 32 °C (90 °F)
Cooling Fans:
CPU 3245 RPM
Chassis 4963 RPM
Power Supply 4327 RPM
Voltage Values:
CPU Core 1.28 V
+2.5 V 2.56 V
+3.3 V 3.28 V
+5 V 5.00 V
+12 V 11.65 V
+5 V Standby 4.97 V
VBAT Battery 2.99 V

 

Welcome to majorgeeks, ShazzerT.
Power surges can do a lot of damage, so rule nothing out. If you have just had it repaired by a reputable pc technition, then ask them to look at it, as it could be related to the power surge.
If only by repaired by a freind, and you want to test the rest, there are many testing and repair, software tools at majorgeeks downloads .
http://www.majorgeeks.com/downloads7.html

 

The first thing that comes to my mind is how do you know it was a "catastrophic power surge"?

That seems to be the sort of thing that you wouldn't be able to diagnose, unless maybe you contacted the electric company in your area.


I'm curious about your system memory. Have you tried to run memtest?

How about your SLI setup? Maybe you could try disabling SLI and running one card at a time.

SLI does tend to be buggy...

 

As Compugate suggests, the graphics cards can cause shutdowns- good point, I had to drop the graphics accelerator down a couple of notches to get mine stable - worth a try.