PSU, CPU or MB?

[CapShot]

Need some insights, maybe anyone went through this before.

 

 

 

I have a Z490 MEG ACE, paired with i9-10900k. A week ago I had a problem when I booted my PC, it went straight to BIOS and loaded defaults. I activated XMP, saved and everything was OK until today. For the record, yesterday I was on the PC for 4-5 hours with no problems, turned it off normaly.

 

 

 

Today the PC did not start, no power. The led on power button on the board is on. I tried to check out the issue. I checked cable connections from PSU, cleaned everything up, removed everything, even RAM. 

 

 

 

My first guess was the PSU. I tried 2 different PSUs, but I only had at hand models with only 1 8-pin connectors to test. The same happens, led on the power button is on when I plug it in, nothing works, PC doesn't start.

 

 

 

Tomorrow I need to try to fix it because I have work to and depend on it. Do I really need the 2 8-pin connectors to at least get the fans going? Or should I look into the CPU/Motherboard instead?