Corrupt CMOS / nvRAM = Win10 doesn't boot, fans stop?

cloneman · July 13, 2017

Something really weird happened to me, my system would stop booting Win10 where it would be frozen on the spinning dots.

I googled this and the solution was the clear the "nvram" by removing the Cmos battery. Suprisingly, that worked! Then I loaded my saved bios settings and everything was still fine.

Before I solved this, I had another symptom - all of the sudden my fans stopped spinning [!]. They'd spin up at boot, then they'd go to 0rpm after POST and they'd stay there. My motherboard does have fan control, but it's never 0rpm. Running prime 95 _normally_ makes them spin faster at 70C, but in this case they were stuck at 0rpm until , well, reboot (for overheat ?).

Asus p7p55d pro [ 1156] Core i7-750

GTX 1070

Anyway I can't reproduce the problem yet, I'm trying to figure out if the "corrupt cmos nvram" as per google was really the cause of both the fans stopping and the Win10 spinning dot freeze. I've now replaced the CMOS battery because it was a little weak.

I haven't been very nice to my computer recently as Claymore miner has been making it BSOD/Reboot (intelppm.sys). If that helps... Nothing else has ever indicated to me that my computer wasn't stable, I always assumed these were CUDA crashes because of buggy mining software.

I mucked around with speedfan and AIDA64 but I doubt thats relevant. Speedfan can't control my fans because the motherboard is set to control them. Also a speedfan problem wouldn't cause 0rpm issues to persist on reboot....

Hard Drive issues were ruled out because, the spinning dots freeze I was able to reproduce on my Live copy of Win10 on USB (before I'd reset the CMOS to fix this)

cloneman · July 28, 2017

I sort of figured out whats going on here.

If I crash with a BSOD for some reason (maybe too much OC) something happens to my bios/cmos. My system won't boot after that unless I pull the cmos battery and reset everything. Everything works fine after that. So, a BSOD, when it occurs, is triggering some sort of bios change or corruption.

Weird, don't know how to fix.