Question Computer won't boot to BIOS - mouse killed it?

[aalkjsdflkj]

My system, which has worked well since I build it in July 2018, suddenly won't boot to BIOS. Literally nothing shows on any display when I start it. Any help would be greatly appreciated. After trying to diagnose it, I'm thinking that the CPU or motherboard are the most likely culprits, then the SSD. Could the new mouse have caused some kind of problem? I just connected the wireless dongle and then used the mouse for a day before these problems started happening.

Timeline:
Purchased and connected an new Logitech G305 Lightspeed wireless mouse yesterday. The system worked fine for a day. I downloaded the G Hub software, and it continued to work.
Today when I went to the computer, it was BSOD. The error was a Windows Stop Code "Clock Watchdog Timeout".
This code apparently is "a miscommunication between the threads in a processor with multiple cores".
I restarted and it worked for a few minutes, then BSOD with the same error happened again.
I restarted then uninstalled G Hub and unplugged the mouse.
Restarted, BSOD again.
restarted, then no BIOS screen. At this restart, the motherboard did light up, fans started, and generally the pieces in the box all seemed to start as normal (typical startup sounds, etc.).
I have not seen any Windows startup screen or any BIOS startup on my monitor after this point.

Diagnostic steps taken so far:

1. Tried a different monitor. Same behavior - no BIOS or anything else displayed on start-up.
2. Tried different positions for RAM (Each stick in position one by itself, then both in swapped positions).
3. Removed GPU and replaced with an old one (AMD 7950 I think). No change.
4. Tried both GPUs in a different PCI-e slot. No change.
5. Verified all plugs / connections. Nothing appeared loose.

System details below. Note that the system is not overclocked, other than the RAM running at the XMP profile it came with.
Gigabyte x470 Aorus Gaming 7 WIFI motherboard
AMD 2700x CPU
MSI Gaming X 1070 GPU
G.Skill Ripjaws RAM 2x8 in positions 1 and 2 as shown in the motherboard manual
Samsung 970 EVO M.2 SSD 1TB

At this point I'm thinking the only way forward it to get a new motherboard and CPU and try to figure out which of those components is not working.

Thoughts?

 

[aalkjsdflkj]

A few additional things that might help.

The motherboard has dual BIOS. I switched to the second BIOS with no change. I'm back to the original BIOS now.
I did the CMOS reset as described in the "No Post" sticky. No change.
I have a Seasonic Platinum 650 W PSU. I am fairly certain it's a very high quality PSU so it's unlikely to be the cause of the problems, but anything can fail I suppose.

 

[aalkjsdflkj]

I put in a known good PSU - no change. I'm planning to order a new MB and CPU. I can't think of anything else that it could be.

 

[shiro5]

Hi, did you fix the issue ? How did you boot to the second bios ?

THanks !