Possible faulty PSU?

[h4nsm0l3m4n]

Hi all, a problem has recently come up on my old desktop computer. I have had it for 4 years now and its worked flawlessly. Recently it has developed a problem where sometimes the computer will not detect the hard drive when it boots up. It just gives an error message saying "Cannot find proper boot device." However if I turn it off and on it works fine. Also when I play games on the computer after a few minutes of working fine the whole computer will freeze up, sometimes it will restart, other times the monitor will turn off, or it sometimes just shuts down too. These include games that I have played for years on the computer such as WOW and Guild Wars. I am pretty sure its the PSU because the other components seem to be ok. The computer doesnt seem to overheat, and everything works ok when its not playing games. Is there anyway to check voltage or something to see if my PSU needs replacing? Or is there another problem that this could be related to that I am not aware of?

 

[g-paw]

First I'd run the diagnostic/repair from the hdd mfg website off a floppy because of the boot up problem and it's easier than replacing the PSU, which is the best way to see if the other is bad.