Bad power supply?

[Big Head Tech]

I've had a few of these in my day. Usually lower quality junk. A PC I built for a friend 3 years ago is rocking a gx650 from cooler master. I forget why we put it in there but the PC is rebooting under load after about 5-10 minutes. The CPU was thermal throttling so I cleaned the heatsink and repasted the CPU and dropped the temps by 30*C. GPU was hitting in the 80s now 60s after I cleaned that. His PC had a ton of dust in it and I haven't gotten over my folks for the compressor. Now it rebooted on me and took 3 boots post video. His PSU then ramped up to 100% fan speed and was noticibly warm. I didn't clean it out yet but I'll probably junk it. I'm hoping it's the psu as he has a 3rd gen i5 and boards aren't cheap and sadly I'm almost out of ddr3 ram.

[GrayTech]

Replace the PSU with one you already own if you can to see wether it is the problem or not.

Keep in mind that opening up PSUs is dangerous. Some parts can even kill you.

[JakeNTech]

Try another one that you know works, or try that one in another system.

[Big Head Tech]

1 hour ago, fixitnow said:

Try another one that you know works, or try that one in another system.

3 hours of Aida64 no reboots.

[JakeNTech]

17 minutes ago, Snaeb said:

3 hours of Aida64 no reboots.

It depends on what you are stress testing, and what rail is at fault, may only be a molex/sata rail that is at fault, assuming there is a fault. It may also be that your rig is consuming more power then the PSU can provide. 

[Big Head Tech]

42 minutes ago, fixitnow said:

It depends on what you are stress testing, and what rail is at fault, may only be a molex/sata rail that is at fault, assuming there is a fault. It may also be that your rig is consuming more power then the PSU can provide. 

I5-3470+R9-270x on a 650W