I have an older system, build 8-9 years ago. It’s been mostly OK, but I had a power issue (no UPS, I know) that appeared to fry my onboard NIC and PSU. No big deal, I got a USB NIC and new PSU and it’s been fine since. Well, I put off looking for UPS, had another power issue, and now my PC isn’t really booting… kind of…

The Mobo is a EVGA X99 FTW. Last night I had it off because I thought it was giving me boot issues due to a bad storage drive and I hadn’t gotten around to pulling it, but it would try to go into Windows, it just wouldn’t get there. It started making some very strange noises - like 2 beeps, the last one lower than the first. I tried unplugging all the drives other than the one with the OS and it still would not boot. I thought it was strange that it would make the noise when already off, so I unplugged it, plugged it back in, and I noticed now it was not making the normal, pre-boot noises.

There’s a small LED number/letter box on the board that is showing a code of C. Per Google, this indicates that there’s an issue with the power connector and the CPU. I tried reseating it, no luck. I think I have another modular connector I can check this weekend, but I don’t think that’s the issue…

While researching the C code, it was running, but not booted. I look over and it’s trying to boot to Windows and it gets in. I was able to download the latest BIOS (which I might have already had installed) and reflashed the BIOS. I also checked Device Manager and noticed that Intel Management Engine had a code 10, STATUS_DEVICE_POWER_FAILURE. I reinstalled the ME drivers. Windows was FINE, like nothing was wrong.

So now, I can kind of get to Windows unreliably, POST is never successful (even if I get into Windows, it just sits there with a black screen and an eventual boot), and the C code is just there on the LED display on the board.

I’m thinking there’s a hardware issue with the CPU even though it worked fine in Windows based on that Management Engine failure. The only thing I haven’t tried is reapplying silver and reseating the CPU. I laso tried pulling the memory and only have 1 DIMM in there now.

Any ideas? Does it seem like the CPU is dead?

EDIT: As I’m sitting in my office, it boot to Windows after several cycles of a reboot showing the BIOS screen. The motherboard keeps making these beeps, like 3 small beeps getting higher in tone with each one. Still with the code C on the display.