Question No Display and Psu issue

[Jachin1224]

Hello, recently I have switched out my MOBO and have had a few issues . For one , the computer does boot up, but no display on screen. Second of all when I flick the switch on the Psu to on, the whole rig starts up. This has never happened to me before , any help would be greatly appreciated thankyou.

 

[richiestang_78]

What are the complete system specs? Also include what mobo you use to have.