I have a 14 month old HP Pavilion P7-1003w
which I upgraded with a Thermaltake 600 watt power supply and an Asus Nvidia GeForce GTX 560.
I went to play a game today and the computer simply lost power. No blue screen. I couldn't get the computer to restart. I unplugged the computer and when plugged back in I am able to get it to boot. Play the game again and it crashes. I ran a program called AIDA64 and if I run a CPU stress test its fine. If I run a GPU stress the computer loses power again.
The final piece to the puzzle is my house did experience a brownout a few weeks ago. I do have a surge protector but I'm not sure how well it handles brownouts.
My suspicion is the power supply needs replacing. But I wonder if the GPU (or motherboard) may have gone bad. I don't have spare parts so I'm not sure how to further troubleshoot without buying something. I'm wondering if people agree that it is most like the power supply or if someone thinks it to be more likely the GPU or has another suggestion. Does the fact I need to pull the plug to reboot point to the power supply or does that apply equally well to GPU or motherboard? (motherboard lights stay green upon losing power)