Solved! Desktop not powering on, next day turned on, the day after that not powering on again

[Jitskamps]

Specs: asus b450 gaming f
Ryzen 5 3600
Corsair vengeance RGB 16gb ram
Msi rtx 2060 gaming z
Cooler master mwe 650 watt gold fully modulair
Cooler master 212 evo cooler

I have this system for a year now

I tried turning on the pc 2 days ago but nothing happened. Tried again next day and it turned on and was stable while gaming. Today I try again and nothing happens.

Please help me identify if it is a motherboard or cpu problem. I have checked the ram, gpu and psu. But those al work. I I have no way of testing the mobo or cpu. The motherboard rgb does turn on. All cables are seated correctly. I tried turning it on by shorting the power pins.

 

[COLGeek]

I suggest you seek help for this on our sibling site at Tom's Hardware.

Systems

forums.tomshardware.com

 

[AlHuneke]

Waiting a day should not matter. Messing around with internal components is just asking for more trouble. If you push the on button and the power light doesn't come on, that points to just a few internal parts. Could be the power switch in bad or the PC power supply (internal). Does the power light come on?

If by "shorting the power pins" you mean the power switch? Since this is a desktop, the power supply should immediately come to life. You can check this by measuring the voltage coming out of one of the power supply connectors.

 

[Jitskamps]

Waiting a day should not matter. Messing around with internal components is just asking for more trouble. If you push the on button and the power light doesn't come on, that points to just a few internal parts. Could be the power switch in bad or the PC power supply (internal). Does the power light come on?

If by "shorting the power pins" you mean the power switch? Since this is a desktop, the power supply should immediately come to life. You can check this by measuring the voltage coming out of one of the power supply connectors.

If I manually activate the psu by shorting the green an black wire in the 24 pin cable, it runs fine and all wire show the correct voltages. It just doesn’t turn on when I try it with the motherboard.

 

[hang-the-9]

If I manually activate the psu by shorting the green an black wire in the 24 pin cable, it runs fine and all wire show the correct voltages. It just doesn’t turn on when I try it with the motherboard.

If system does not turn on at all, most likely issue is the power supply or the power button, maybe motherboard. CPU is one of the least likely components to fail.

 

[AlHuneke]

Great. You're most of the way there. The power-on signal (green wire, pin 16?), when momentarily connected to ground (any of the black wires if they follow the standard), will turn on the PSU as you discovered. The unit power switch probably connects to the motherboard via a small connector. Unplug that and try to short across those pins (very carefully!) which should start the PC. If it does, the problem is the panel switch or, less likely, the wiring to the switch. You just need to trace things with your ohmmeter. If the problem is the MB, that should be just a direct connection to the PSU PwrOn signal.

Be careful about what you try as I don't have a schematic for your unit. I haven't touched a desktop PC for a long time but what I described is how they used to work. Let me know what your find.