No Signal on monitor after reboot

[Vikz12]

I went to upgrade my PC's processor so i bought it home and started playing some games afterwards I restarted my pc so when I restarted my CPU was working fine but my monitor says no signal detected. it was fine before upgrading. Please help me.

 

[cin19]

Can you post your pc specifications? including the old and new cpu.

 

[Vikz12]

Can you post your pc specifications? including the old and new cpu.

The specifications are
Motherboard : z87 G45 Gaming
Graphic Card : GTX 750 ti
Processor : i7 4790k

The CPU is a cheap cpu the name is goldskits
Monitor : BenQ