Question My PC boot only when unplugged for several hours

[gmenezes]

I just assembled a new computer with the following components:

• Ryzen 7800X3D
• ASUS TUF Gaming X670E-Plus
• Lian Li Galahad Trinity II
• RTX 4070 SUPER
• Kingston Fury 6000MHz
• 990 PRO 2TB
• MSI MAG 850W
• NZXT H9 FLOW

Currently, my PC is mounted on a bench outside the case. The first time I tried to turn it on, I heard the GPU fans and the PSU fan spinning, and then I heard a click from the PSU before everything shut down. I checked if the cables were securely connected and tried disconnecting all components, leaving only the memory, CPU, and SSD connected, but I had no success. The next day (24 hours later), I got home from work and the computer turned on normally. However, when I turned it off and tried again, it wouldn't turn on, and the same problem repeated. The next day, I tested it with another PSU from a friend, and the same issue occurred: the computer turns on, but does not turn on again after being shut down, and the same happens with the other PSU.

Do you have any suggestions on what might be the problem? I have never seen anything like this before.

 

[Lutfij]

Welcome to the forums, newcomer!

Bench? Might want to see if the system behaves the same when breadboarded(not on your testbench). It seems to me like you're having a grounding issue. Might want to also relocate to another wall outlet.

 

[gmenezes]

Thanks for the response!

Yes, I initially assembled it in the case, but when the problem occurred, I removed from the case the MOBO from the case.

I tested it in another wall outlet and the problem persists. Do you have any other ideas?

Thanks again!

 

[SkyNetRising]

Do you have any suggestions on what might be the problem? I have never seen anything like this before.

Unplug PC from power.
Press power button, to discharge PSU capacitors.
Connect PC to power again.
See, if it starts.

Suspect your PSU.

 

[gmenezes]

Thanks for the response.

It worked once, but not the second time. How long do I need to do this? Actually, I am using a screwdriver to turn it on, since it is on a test bench. Do you think it's the power supply? I tested it with a friend's power supply and the same thing happened.

It's a crazy problem.

 

[gmenezes]

I noticed that if I remove the power cables from the CPU, the PC always starts up normally.

Do you think it could be the motherboard or CPU? Or could there be another possibility?