After installing new PSU pc wont turn on

TheOneAndOnlyEcon

Commendable
Mar 16, 2017
15
0
1,510
I upgraded my pc to a 700W psu because i needed more juice. After plugging everything in, the motherboards led lit up green, but when i pressed the power button nothing happens. I made sure everything was plugged in correctly. I also swapped back to the old psu, and i can't get it to work anymore. So basically my pc is dead at the moment. Is there a chance some cables got unplugged? I checked the power button, its safe and sound.
Did i possibly fry my motherboard?