Strange PC behavior?

Question

Computers

Good evening, in general the problem is this. There were problems with the audio input on the front panel of the PC, I decided to try to disable the front USB ports. Removed the cover, disabled the ports. I press the start button, the coolers spin and nothing else (there is no speaker). The mouse and keyboard also do not react in any way, I have already broken my head and I can’t understand what the problem is.
From what I tried: I changed the RAM, cleaned the contacts. I took out the vidyahu, tried to start it on the built-in one. I reset the Bios, cleaned the contacts, the PSU looks normal, the conders are intact.