Originally Posted by darien
I connected 2 old power supplies and my current power supply to the old PC one at a time. I sat the old PC next to my current PC and connected a power cord to one of my current PC's fans then turned on the power of my old PC. The two older power supplies made the fan in my new PC turn on, but my current 600W power supply did nothing. So does this mean my power supply is definitely broken? Or is it just not compatible with my older PC? Both the older power supplies came with prebuilts and are under 300W and without the extra 4 pin connector. The motherboard in the old PC also doesn't take the extra 4 pin connector, so with my 600W power supply I just left the 4 pin unplugged.
if you open your psu, you will void the warranty if it didnt already expire.
correct me if im wrong, but the extra 4 pin, supplies power the the cpu, so it shouldn't affect the power delivery to a 3 pin fan. most likely your psu is gone.
but one last thing you could do, is disconnect your gpu and hard drives, and see if your motherboard will post. kinda like what you do when you first build the pc.