Question Pc won't turn on

[Redsyrup]

Hi, so I recently had an issue with my PSU so I ended up taking one from an old pc of mine and replacing it with the dead one. Then I went on to turn on the computer, the power switch didn't wanna work, at first I assumed that the old PSU was also dead but then I pressed the reset button and the cpu fan started spinning but the screen was black. I unplugged the power cord from the psu and tried turning it on again, only this time, the reset button stopped working too. I'm lost and Idk what the issue is. Should I buy a new psu or maybe the psu isn't the issue? Help

 

[rgd1101]

full system spec? include make and model of the psu