PC Won't boot with CPU Power Plugged In?

[ssmacc]

Hello All,

Not sure if this can be answered!

A friend turned on his PC last night and nothing happened...no fans spun etc (although PC case lights are on)

After going through all the normal checks (no loose cables, 1 stick of RAM etc).

I tried the power cables...turns out the PC turns on without the 8pin CPU power cable plugged in, although nothing on screen (so doesn't boot), but CPU fan spins etc?

A long shot, but has anyone else experienced this?
I assume it's either a Motherboard fault or possible PSU issue?

Any suggestions welcome!

Thanks,

 

[ssmacc]

Cheers for the response.
It's a AM4 based PC, it has a dedicated GPU, not sure of the model...maybe a 980 or similar.

I'm going back on Sunday and will try a different GPU, I think it must be something to do with the CPU power...It's a strange one!