Instant Power when plugged in

[kirbyrj]

I have an older high end PSU from maybe 3 years ago that whenever I try to use it, it gives instant power to any motherboard I plug it into. Fans start spinning as soon as I flip the switch in the back. Both boards I tried it on are outside the case so there is no shorting taking place. I had this problem before, and I just turned the PSU off and unplugged it for a little while and plugged it back in and it worked. Now it doesn't even do that.

Any ideas how to fix this?

 

[kirbyrj]

No one? I solved my own problem by just buying a new PSU, but I'd still like to know if anyone has any ideas on the problem .

 

[silent-circuit]

Hmm... maybe there's an internal short, or a short in the 24pin main motherboard connector? Also, why are you plugging it in to any motherboards with power from the wall connected in the first place? Not a good plan.

 

[kirbyrj]

Hmm... maybe there's an internal short, or a short in the 24pin main motherboard connector? Also, why are you plugging it in to any motherboards with power from the wall connected in the first place? Not a good plan.

I figured there might be a short somewhere. Actually, I probably misdescribed the situation. The ATX connector is connected, and then when I plug the power cord into the back of the PSU the fans start right up.