Power supply squealing

[Gr33ned]

Just assembled another computer. As soon as I connect my PSU 24 pin to the motherboard (computer is off), a high pitch squealing comes from the PSU; so I tried the PSU on another computer, and it worked fine, there was no PSU squealing. I thought at first it was therefore a mobo problem, however when I connected a different PSU that I know works for sure to the mobo, it works as well. I am not sure what the problem is!

 

[ko888]

What is the make and model of the PSU that doesn't work?

What is the make and model of the PSU that does work?

What is the make and model of the motherboard and any discrete graphics card(s) installed?

 

[clutchc]

Were you trying to connect your 24 pin cable to the board with the PSU turned on?