Black screening

[openchut82]

I have had this problem for a few months now. While playing BF2, my computer just shuts off completely. Has only shut down while playing BF2 usually for a hour or more. Sometimes twice a night, and sometimes not for 3 or 4 days. Can immediately turn PC back on and start playing BF2 with no problems. CPU and video card temps usually around 65c but not over 70c while playing BF2.
System as in my signature.
Using Windows XP Home upgrade.

What I have done so far:

Replaced power supply. Had Antec Neo TPII 430 watt. Now have Enermax Liberty 500 watt.
Borrowed ram for a day and switched ram to 2x1gb Corsair. Now back to 4x512 sticks.
Replaced hard drives to two new WD80gb in raid 0.
Reformatted twice.
Ram set at DDR333 or DDR400 2t. Makes no difference.
Heard of ZA and CA antivirus having problems. Deleted CA antivirus.
Have set BIOS to default, cpu to default, video card to default with no help.
Have tried two different Video card drivers.
Nothing I have done so far has helped.

Potential problems I can think of:
Video card bad, although dont get any artifacts, just completely shuts down.
Motherboard bad
CPU bad
Power supply, could I have had two bad power supplies? Sounds like a power supply issue to me.

Any suggestions would be greatly appreciated.

 

[valis]

i'd use memtest and test the ram first, then go from there, how are your temps during gaming?

 

[openchut82]

I have ran memtest all night and most of the next day and all is good. Temps posted are during gaming.

 

[openchut82]

3D Mark 05 will run and have gotten 8900. If I overclock above 2.8 then 3D mark will shut down but stay at desktop. But all is at stock now. Only happens during gaming.