post OC non-booting - help required

JohnTedd · 23 May 2011 at 09:44

I spent all day yesterday trying different cominations of overclocking permutations including upping Vcore quite significantly. I had plenty of bluescreens along the way but could change settings to get a working system again. I also had my watercooling augmented with my aircon unit to see how far I could push my rig. At the end of the day I turned off the aircon and reverted my BIOS to the same settings that I had been running with for months but now it won't boot

I can get into the BIOS w/o issue, but when I try to boot either Windows or Ubuntu they both fail quite early on. Ubuntu will run its memory test OK, so it seems to be some sort of driver issue. In windows case it's when the Windows 7 logo is colliding (so quite early). In Ubuntu's case I sometimes see the Ubuntu logo in white but often it's just a blank screen before the PC reboots.

The last test I did was to run 3DMark Vantage. I had both the CPU and the 2 GPUs overclocked (using ASUS SmartDoctor). When I closed SmartDoctor I agreed to keeping the overclocked settings. Perhaps that was my mistake and it's loading the GPU driver that causes the issue. Could that cause the whole PC to crash/hang?

Another possibility is that I have enabled fast boot in the BIOS. Not sure precisely what that does, but perhaps it is caching something it shouldn't? Could that be the cause?

I have tried reverting the tweaking back to the factory settings without any improvment.

Any ideas what could be wrong?

Amraam · 23 May 2011 at 15:29

Is your vCore definitely back to normal?

JohnTedd · 23 May 2011 at 15:40

As best as I can tell. I set it to "Auto" in the BIOS and when I go into the BIOS it claims to be something sensible. Of course when I leave the BIOS it restarts the PC so I can't 100% tell what settings are actually being used until I get into the OS and can run Gigabyte's easytuner app....

JohnTedd · 23 May 2011 at 18:40

I have now booted it. I set the # cores of the CPU to 1 (instead of the 6 it has) and turned off hyperthreading. I guess I'll now have to enable more and see what happens. But it looks as though I have done something to at least one of the cores

JohnTedd · 23 May 2011 at 19:01

I have now got it booted with 2 cores and hyperthreading enabled. I did try 3 but that failed. Whether that means 4 are bad, or just the 3rd core I can't tell. Does anyone know a way to find out more about the health of the CPU?

Anyone got any advice on RMAing this sort of semi-working CPU?

JohnTedd · 24 May 2011 at 09:45

I contacted my supplier and they no longer stock this chip, so I have to go to Intel and get a replacement. I have started that process and I will let you all know how it goes.