Question Replaced MB and CPU, STILL no post beep, system powers on, GPU fan spins once then stops

Jul 6, 2021

I have been dealing with a hell of a problem

My original computer:
OS: Windows 10
CPU: Intel 7700k (upgraded now to 10700k, still not fixed)
PSU: 650W (replaced with new 850w, still not fixed)
ROG STRIX Z270F GAMING (replaced with ASUS Prime 470-P, still not fixed)
Graphics Card: Nvidia
SSD1: Samsung 960 Evo M.2 NVMe
SSD2: Intel 670p M.2

It'd worked great for many years. When I installed that new Intel 670p, it would still boot but the data drives disappeared. Found out it was because of SATA stuff, tried changing BIOS settings and that didn't work, so I swapped my SSD drive locations and that is when suddenly my computer wouldn't POST anymore from then on. Nothing I did could fix it.

So I bought a new Asus 470-P Motherboard and newer intel processor, rebuilt the system, stupidly and put the SSD drives and everything thinking it would work since it's a new MB and CPU. It never posted. Took everything out, still no POST. Not sure but seemed like the new SSDs may have corrupted this new MB too somehow, but resetting CMOS and everything doesn't work.

I have followed the Tom's Hardware troubleshoot on it and done just about everything:
  1. Taken the MB out and reassembled it outside the case, it turns on but does not post, same as inside the case.
  2. I have tried to do the CMOS reset probably 20 times, taken out the CMOS battery for hours, etc. nothing works.
  3. I have removed EVERYTHING down to barebones, with 1 stick of RAM, or 0 RAM, with the GPU and without the GPU, with nothing except the processor and the keyboard plugged in and still can't get it to post but it seems like EVERYTHING works EXCEPT it won't POST, no beep.
Two interesting things: The CD drive works, the CPU fan will always spin while turned on, but the graphics card fan only initially spins for about 3-5 seconds while everything is powering up, then stops completely. The keyboard has an initial flash whenever I turn on the computer, but caps lock, nums lock etc won't light up after that. Also the Asus Prime 470-P motherboard has a yellow glow behind it, that kind of slowly fades and grows (maybe that's normal though, I wouldn't know since I never got the new MB to work).

There is never a beep, so it's clearly not able to POST. As I replaced the CPU and sold the prior one (which the new person used just fine), it's not the CPU apparently.

What is going on? I've been trying unsuccessfully to fix it for 3 months, I keep giving up for weeks and just use my laptop only to retry to fix this $800 failure of a machine. I'd offer to pay someone $200 to fix it but without any guarantees it seems hopeless and I doubt anyone locally can figure it out better than me and you guys. It seems like the SSD drives somehow infected the Motherboards to not post even when they are taken out of the machine but I don't get how the heck they do that and how I can reset the MB.