Cpu wont boot after graphics card and psu change..

[anasahmad17]

hi guys jus installed my new gpu and Corsair cx430v2uk power supply and then when i tried to start my pc it wont boot..
nothing is showing up on screen.. all the fans and components are working but the screen is black not even bios shows..
what can be the problem?
plzz replyy!

 

[RealBeast]

Did you plug the ATX12V and graphic card power connectors in?