On an as rock z77 extreme4, bios 2.50, i5-3750-k, gigabyte rad hd 7970, 850w corsair PSU, haf xb case with full complement of fans. No oc'ing yet, build is about a week old. Pc keeps stopping and going to black screen after being on for about random intervals and, on the next one to two reboots, it stops booting without posting anything. Dr Debug will claim b2 (lower case b, not a 6 I'm pretty sure). On the next reboot, it goes past b2 to 99 to a2 and starts normally until it fails again the same say.
The repeated reboot bringing it back again leads me to think there is a problem with heat somewhere, so I check. Idling the system at 27c CPU, 25c MB. Under load (maximum strength Unreal Tournament 3 at 1024x768), peak at cpu 45c, mb 30c, and 41c peak GPu. Def not heat.
Freezing on a black screen makes me think graphics, but not starting up again immediately makes me think mobo.
So far, been a beast of a machine, but i can't have these random bouts of narcolepsy. Not interested in a sleeping giant.
Reseated ram, still being a little drama queen. A friend suggested I test my power supply, a Corsair TX850. Tested with a TT Dr Power 1. Six of the seven lights in the circle come on. -5v light remains off. Don't know if that's normal. Any new ideas?
Discovered something strange. I had noticed that while the pc slept, my Logitech G15 was still getting power and the backlighting was flickering. It was plugged into USB 2.0. Moved to USB 3.0 after latest test and now the backlight doesn't come on. Wonder if related or just another superfluous data point...
This system is connected to three displays: Two monitors and a plasma TV. The CPU is also overclocked but always kept cool, idle temperatures ~36C and ~65C with Prime95. At the moment it is only overclocked to 4.0 GHz with voltage offset +0.020v.
No matter what the configuration in terms of how many displays the graphics card outputs to and in terms of CPU overclock, the system occasionally crashes with black screen and the Dr Debug error b2 shows up when trying to reboot. Sometimes it cannot POST and requires a CMOS reset. Usually a hard reset is fine and Windows restarts.
I have tried reseating RAM, reseating CPU, cleaning out dust and I have also totally dismantled the graphics card and cleaned off the dust and applied arctic silver thermal paste and put back together.