2-year-old PC suddenly fails to boot correctly

Sammich

Distinguished
Jan 1, 2003
2
0
18,510
When I turn the power on, the screen barely flickers, then goes blank. The mobo then returns an error code of d6, which means there is a problem with the display adapter. I tried the regular troubleshooting steps: different HDMI cables/ports, removed the video card and tried booting from onboard video, cleared CMOS via the button and via jumpers, removed all expansion cards and all SATA drives, swapped each stick of RAM into and out of each slot. Same result and error code each time.

I happened to remember today that I had a similar problem when I first installed the CPU/RAM and tried booting. Sure enough, the "fix" for that worked with this as well: if I keep hitting Delete after I hit the power button, I can get to the bios, and from there I can successfully get to Windows as normal. Back then, it was just a one-time thing, but now it does it on every startup. I'm not sure if this is harmful, but it's certainly annoying. Any ideas on how to isolate and/or solve this issue? Specs below:

Asrock Z77 Extreme4 motherboard
i5 3570k CPU w/CoolerMaster Hyper 212 Plus
HIS IceQ Radeon HD 7850 video card
2x Samsung 8GB RAM (not sure of the model #; purchased in 2012)
Samsung 830 series 128 GB SSD (OS)
Crucial 256GB M4 SSD (data)
Asus Xonar DG sound card
Corsair AX750 PSU
Win7 home premium
 
Solution
Turn the power off then unplug the cord. Now try removing the GPU and cleaning its contacts and reinstall it and see if that resolved the problem.