Question PC doesn’t turn on when CPU power cable is plugged in

[Mushee]

Hello! I Just started building a new pc, but open trying to turn it on, a quiet high pitch wheeze comes from my psu and nothing comes on. (no lights, no fans, nothing) I then started to trouble shoot, as I did that I noticed that the PC only turns on when the CPU power cable is unplugged, it doesn’t matter if it’s only plugged into the MOBO or the psu, but if it’s plugged into both it doesn’t turn on. at first I thought maybe the socket on the psu I was plugging the cable into was bad, so I plugged it into the one my GPU was using, still the PC didn’t boot. I then took my cooler off and inspected my cpu and MOBO, everything seemed fine, nothing looked burnt, but just one pin was slightly bent and it still managed to fit perfectly into the socket.
At this point I’m pretty sure it’s either the motherboard, the cpu, or the cpu power cable. But I’m not sure and don’t know how to test them to single it out. Help would be much appreciated, thank you!

EVGA GTX 1080 FTW
2x8gb 3200 c16 g.skill trident Z
Ryzen 7 1700x
B450 tomahawk max
CX750M (semi modular)

 

[Vyrvelata]

Usually... 8 pin for the CPU is.... CPU only!
Don't plug that into your GPU, or plug GPU 8 pin into CPU 8pin on the mobo.
I don't know what brand PSU you have but... usually in every proper PSU... its visible which 8 pins are for GPU and which for CPU.
Just try different PSU... from a friend maybe.

 

[Mushee]

Usually... 8 pin for the CPU is.... CPU only!
Don't plug that into your GPU, or plug GPU 8 pin into CPU 8pin on the mobo.
I don't know what brand PSU you have but... usually in every proper PSU... its visible which 8 pins are for GPU and which for CPU.
Just try different PSU... from a friend maybe.

Both my gpu and cpu sockets on my MOBO are ATX, I didn’t plug the cpu cable into the gpu or vice verse if that’s what you were thinking.

 

[Cheese Dripper]

"a quiet high pitch wheeze comes from my psu and nothing comes on."

What PSU do you use? any weird sounds coming from your PSU may mean it's fried/dead so definitely try another