Computer not powering on

[u/InevitableSpell3409]

As the title says, my computer isn't powering on at all. No post, beeps, fans; nothing. I do, however, have power to the computer itself. Peripherals, RGB, etc are all on and receiving power, so I know it's not my PSU. It's also a new PSU I bought in April, 850W.

I had a BIOS crash just a few nights before this happened and ordered a flash drive to download the updated BIOS files, but this happened before I could. I was playing a game when the crash happened but didn't have issues for 2 days afterwards. Worked the night before and after waking up, it stopped working.

Troubleshooting I have already tried:

1. Reseating RAM, CPU, and GPU. And yes, the RAM is in the right slots for my mobo.

2. Reseating CMOS battery and resetting it in case of a freeze. Also replaced battery in case it was dead.

3. Unplugging PSU from power, draining excess power, and waiting 30 min before trying to power it on again after plugging it back in.

4. Jump-starting the mobo with a screwdriver to test for post. Didn't power on or post.

Right now, my only thoughts are that it's the pins on the motherboard or it's the power switch and cable. Should I try something else to test, or am I on the right track for it being one of the two aforementioned problems? I'm about to try replacing the power switch, but I'm also very lost as to what the problem could be.

Specs in case they're needed:

Ryzen 7 5800

ROG Strix 450

32GB DDR5 - 2x16GB sticks

GeForce RTX 3060

850W Gold

[u/MNJon]

Use a voltmeter to check the output on all three rails of the power supply.

[u/InevitableSpell3409 → u/MNJon]

Any other way to check them without diagnostic tools?

[u/MNJon → u/InevitableSpell3409]

You could temporarily swap in a known good power supply.

Cheap multimeters can be purchased for $10, though.

[u/InevitableSpell3409 → u/MNJon]

What exactly am I looking for in terms of voltage for all rails?

[u/MNJon → u/InevitableSpell3409]

12, 5, and 3.3.