I've been having a problem with a computer and I just can't figure out what's wrong. Randomly most of the time the screen goes blank and says no signal but everything in the case is still running, other times everything freezes. I check the Event Log after but it never has any errors. This doesn't happen everyday but sometimes it happens multiple times per day. I just used memtest overnight with no errors, I'm now using Prime95 to test the CPU. Heat isn't the issue as temps are all normal. What can I use to test the GPU? All drivers/firmware/BIOS is up to date. Are there any other tests I could run to troubleshoot?
OS: Microsoft Windows 7 Professional x64
Motherboard: Gigabyte GA-990FXA-UD5
PSU: Corsair 850AX 850W
CPU: AMD FX-8120
CPU Cooler: Enermax ETD-T60-VD
RAM: Mushkin Enhanced Blackline 4GB DDR3 1600 996988 x2
GPU: EVGA 460 2Win 2GB
HDD: Crucial M4 128GB SATA III
HDD: Western Digital Caviar Black 640GB SATA III
HDD: Western Digital Caviar Black 2TB SATA III
ODD: Samsung SH-B123L/RSBP
Tuner: Hauppauge! Colossus HD PVR
Tuner: Hauppauge! DCR-2650
Sound: ASUS Xonar D2
