All of a sudden my rig wont power on. Help meee

Idk what happened. I was going to add risers. I plugged them in and after it was set I went to test but it wasnt powering on besides a quick flow of juice. So I removed the risers amd unplugged the newly bought wires that I plugged into the psu. And now nothing. I flick the switch on the psu, the power flows thru the mobo real quick (I see the slight lights turn on for a sec), I go to power it up and nothing happens. Wtf did I do