Question Computer not starting

Aug 15, 2022
Hey guys, I’m having some issues right now with my computer not powering up.

Computer specs:

CPU: AMD RYZEN9 3900XT Socket AM4 (3.8Ghz+64Mb)
RAM: 4x 16GB of 3200MHz Crucial Ballistix Desktop Gaming Memory Kit, red
GC: Gigabyte GTX N970IX OC-4GD 1076 MHz 4096 Mo PCI-Express
SSD: Samsung SSD 970 EVO Plus 1TB Nvme M.2
Noctua CPU fan NHD14
4x be quiet! Pure Wings 2 140mm PWM
Case: Be quiet! ATX Pure Base 500DX
PSU: Corsair 750W 80+ Gold RM750X (high tier)

This build was running smoothly for 18 months. But I started experiencing random black screens (disconnected GPU) + error message about the display driver not working properly when working on Premiere Pro. So I decided to:
  • Update the graphic drivers
  • Reinstall Premiere
  • Update the MB Chipset drivers
  • Update the BIOS version
  • DDU + reinstall the newest graphic drivers
  • Check the Power Plans Options, SFC Scannow
I was still experiencing the black screens so I decided to swap my GTX 970 for another one I have running in one of my slaves computers. While swapping I decided to use an air duster on the case and components to make sure dust was not responsible for the black screens.

Since then the computer would not start: when I push the Power button, nothing happens. Fans are not starting, nothing.

So I decided to:
  • switch the 970 back
  • Swap the PSU for a 650W Seasonic 80+ Bronze
  • Remove the MB power extension and plug the PSU directly to the MB (unfortunately I can’t do the same with the CPU power extension blocked by the Noctua)
  • Remove the Power switches from the pins and try to start the computer with a screwdriver (nothing happened)
I don’t think the PSU is defective because I still couldn’t start the computer after swapping with the Seasonic PSU, and the MB RGB leds are on with these PSU are switched on.

I don’t think the GC is the reason the computer is not powering up because it wouldn’t start with either GTX 970 and the slave computer starts normally with one of these cards.

Power chord is not faulty because it could start my slave computer.
Outlet is not faulty because it could start my slave computer.

I didn’t try to remove the RAM sticks yet because I would need to remove the Noctua to proceed, reapply thermal paste on the CPU etc

I can’t swap CPUs with my slave because one is AMD and the other is Intel.

I so t know what to try next so each one of your suggestions will be helpful.

Aug 15, 2022
I used the same generic Air Duster I have been using for years (it wasn’t a new can btw), ordered on Amazon. You think I could have damaged something with it?

The computer was turned off, I actually sprayed the air duster outside, in open air for 5 minutes.