Pc won’t boot

[potatopc04]

I replaced my PSU and when trying to boot it says hard disk not found or something like that. And then it restarts after a fast blue screen.

 

[SirSub42]

Did you make sure to plug the power connector back into the hard drive?
Can you access your bios to see if your hard drive is recognized there?
Try connecting to a different port form your motherboard to hard drive.