Question PC not posting/needs multiple restarts to boot properly

[legro21]

So about a year ago I build a new PC with the following specs(All brand new):

CPU: AMD Ryzen 5 7600x
GPU: NVIDIA Geforce RTX 4070
MOBO: MSI MAG B650 TOMAHAWK WIFI
RAM: G.Skill Trident z5 Neo
PSU: Corsair RM850x shift
Storage: Kingston KC3000
CPU cooler: Peerless Assassin 120 SE

At the beginning I had no issues whatsoever, but a few month ago I ran into a problem where my PC wouldn't wake up from sleep properly, it would turn on, fans spinning but didn't display anything and the debug LEDs for CPU and RAM would be on. Turning the PC off and on again would usually resolve this problem, however a while later I started having this problem when turning the PC on(CPU/RAM lights on and fans spinning, not displaying anything, RGB from fans somtimes on, sometimes off). The PC would usually fix itself after a couple of restarts and once it's on it works perfectly fine and I didn't find any Problems during tests. However sometimes instead of a couple of restarts it takes hours for it to work, when that happens I tried some things to fix it but without any results.

Things I've tried:
1. Reset CMOS battery
2. Flash BIOS
3. Reseat GPU/use internal GPU
4. Use only singular RAM sticks in different slots
5. Turn on without SSD

The problems seems to be getting worse since now I'm at a point where my PC hasn't posted anything in well over a day, my best guess is that it's a motherboard issue or maybe PSU.
Any idea on how to fix it or at least determine what part exactly is causing the issue?

 

[Lutfij]

Welcome to the forums, newcomer!

Flash BIOS
What BIOS version are you on for your motherboard?

Reset CMOS battery
Once you've verified your BIOS was flashed tot he latest version, disconnect from the wall and display, then remove the CMOS battery, press and hold down the power button for 30secs and then replace the battery after 30mins.

It would most likely be a board/BIOS issue but you'd need to drop all of your parts onto a known working motherboard(a friend's or neighbors) to see if you the same issue crops up on said donor motherboard/platform. If you suspect it to be the PSU issue, you can try powering the system without the discrete GPU(using the iGPU instead) and later on then source(borrow, not buy) a 650W reliably built PSU and see if the issue persists with your existing hardware.

 

[legro21]

I tried resetting CMOS battery with both the newest beta and non beta BIOS version, but to no avail.
Guess I'll try to get a spare board and PSU to swap with the ones I have.
Only reason I'm suspecting PSU is because I found a post with a similar issue where it turned out to be the PSU was causing the problem.