My pc turns on but the screen stays black, I have taken mono out of case and started it but the CPU fan does not start. Can an

[HaZardly]

I just finished installing a new mobo and ssd in my case and now my pc won't boot, and the screen won't recognise the pc. I have taken the mobo out of the case and connected the power the light on the mobo comes on but the CPU fan does not.
The mobo I am using is an Asus pbh77-m le.

 

[Analgetic]

Did you plug in the cpu power connector?