Power (watts) = Current (amps) x Voltage (v). Older power supplies output mostly at 3.3v and/or 5v. However, videocards take 12v electricity from the PSU. Meaning, it wouldn't matter if you have a 500,000 watt power supply if it outputs that at only 5v. Furthermore, bad power supplies have a propensity to
blow up well before their rated load. It's best to just tell us the exact model of power supply he has, as that could be the problem. It could also be overheating, or perhaps bad memory. One of my clients (friend

) had an ASUS 9600GT BLACK PEARL which could not run the default memory clock, which would often result in a black screen.
However, what happened here is not clear. Does it not turn on AT ALL with the videocard fitted? Or just crash during gaming requiring a forced restart?
In any case...:
1. Does the computer boot at all with the videocard? Or just crash within games?
2. What power supply is it, get the model, it should be on the side of the PSU.
3. What motherboard is it?
The first thing I would do is try the videocard on another computer that is reasonably similar to the problem pc. That's how I found out it was the 9600GT at fault. I put the 9600GT into my PC where the same problems developed - so it must of been the videocard. Took about 5 minutes. (And since he is too lazy to return it, the memory is now underclocked by 50mhz
Last edited by Slotback on Tue Nov 03, 2009 8:05 am, edited 1 time in total.