Question PC doesn't turn on, fans at full speed, no POST and CPU LED on. Help!

[parama3500]

As I press the power button, not even it's LED turn on, however the fans spin at full speed (in a normal startup the fans are at full speed for a brief 2 seconds or so, except in my case they remain at full speed, probably indicating no POST)

CPU LED on the mobo lights up with no video output, the keyboard and mouse gets power but pressing the caps lock do not light up the LED.

This issue bothered me for the past 2 months occasionally (mostly when I had a power outage, but rarely this issue triggered when waking up from sleep as well), except I was always able to solve it by just turning it off by the PSU switch followed by a regular start up.

Last time it happened, the simple PSU turn off trick didn't work & I had to troubleshoot (mentioned below) and it solved the problem for 4 days and now the problem persists.

On these 4 days it worked like a charm, no indication of any failing parts. This made me quite skeptical about the EZ debug LED saying something is wrong with the CPU

But this time tho, not even those troubleshooting steps worked, I've tried these;

Reseating the CPU, checking for bent pins, repasting
Reseating the RAM, trying other slots
Reseating the GPU
Reseating the CMOS batters and hence resetting BIOS

There's no dust build up, and I don't have any overheating issues. The PC is only 2 and a half years old and all the parts were bought brand new.

Ryzen 5 3600 (Stock, No OC)
MSI B450 gaming pro carbon ac
Corsair Vengeance LPX 8GB 3200 MHz
ROG Strix GTX 1660 Ti
Corsair CX650M

What can be the issue? What additional details do you need?
Any help is highly appreciated!

 

[Ralston18]

Noted PC being 2 1/2 years old.

PSU = Corsair CX650M . Original PSU? History of heavy use for gaming, video editing, or bit-mining?

Look in Reliability History and Event Viewer. Either one or both may be capturing error codes and/or warnings relevant to the problem(s).

Increasing numbers of errors and varying types of errors suggest a faltering/failing PSU.

Start with Reliability History. Much more end user friendly and the time line format can reveal both problems and patterns.

 

[parama3500]

Noted PC being 2 1/2 years old.

PSU = Corsair CX650M . Original PSU? History of heavy use for gaming, video editing, or bit-mining?

Look in Reliability History and Event Viewer. Either one or both may be capturing error codes and/or warnings relevant to the problem(s).

Increasing numbers of errors and varying types of errors suggest a faltering/failing PSU.

Start with Reliability History. Much more end user friendly and the time line format can reveal both problems and patterns.

It's an original PSU, and the PC wasn't used for heavy gaming all that much, around 15 hours gaming for a month at max, no video editing nor mining.

I can't check reliability history or event viewer cause I literally can't get this thing to post and boot into windows 🙁

Also this PC never crashed while I was using it, it mostly had this issue while turning it on after a shutdown, or rarely after waking up from sleep, so not quite sure how I could get any logs regarding to this.

Thanks

 

[Ralston18]

Will the PC boot into Safe Mode?

Try replacing the CMOS battery - just as a matter of elimination.

Do you know anyone that can loan you a PSU for testing purposes?