Clock Watchdog Timeout

So I have a gaming machine which worked fine for a year and a half, then suddenly started crashing almost immediately upon booting, and throwing a BSOD with a CLOCK WATCHDOG TIMEOUT error. Specs are as follows:

Asus ROG Z370-E mobo
16 GB DDR4-2133 RAM (2 modules matching)
Onboard video
Intel i7-8700 (not overclocked)
Win 10 x64

I started by doing a completely clean install of Windows, but it didn't resolve the issue. I've tried a single stick of RAM, in each channel, no dice. I've tried booting into a live version of Ubuntu, it won't complete the load. I even wen't so far as to replace the motherboard with a brand new ROG H370-F, same situation. I'm now thiking it's the CPU, but before I run off and buy a new processor, I wanted to get some different opinions on the situation. Side note, sometimes it will crash before it gets to the Windows login screen, and it gives a WHEA UNCORRECTABLE ERROR on the BSOD. Thoughts?

 

Both BSODs are pointing to hardware/Bios bug/ driver/driver corruption but given the failed Ubuntu loading it's unlikely to be Windows driver-related.

Start at the top, dismantle, check and refit all connections, check all CPU pins, check/install any BIOS updates, reset BIOS to safe defaults and disable any hardware/fluff you don't use in the BIOS.

Minidumps might help narrow it down further if you can access the System drive.

 

Yeah agreed on the driver thing. With regard to refitting everything, I installed a brand new motherboard, so all the connections were re-seated. It also had a default BIOS, so I don't think it's a settings thing in there. Even I wanted to update it though, I'd be afraid it would crash during the install and brick my mobo....

 

Understood. How about trying to find a local shop/workmate/contact with a compatible 'board/CPU that could be used to troubleshoot?

 

Yeah that would be ideal. I'll have to ask around. I mean, what else could it be though right? I should have mentioned before, I tested the PS also, it checked out good.

 

It's very difficult to test PSUs under the real world loads that booting and running/gaming/benchmarking a PC requires. The PSU's a possible cause but the only way to be sure is by installing a known-good quality unit of adequate wattage and trying it, or using yours in a similarly powerful machine .

You've pretty much ruled out motherboard problems, unless both original and new have the same fault. CPUs are generally the strongest link in the chain, failures are very rare.

 

Yeah I agree. That's why I'm leery of going out and getting another CPU. I just don't know what else it could be. There's not really anything left that could have failed...

 

The one time I had a cpu failure, the symptoms were that the pc just suddenly froze.

It would boot fine and after an irregular period of time, the o/s would just freeze.

Devil of a job to find out what was wrong as I tried new, mobo, psu, ram, vga eventually the only thing I hadn't replaced was the cpu.

 

That's basically where I am now, and the exact same symptoms! It's really the only thing left...