New PSU Installation, gone bad

Hello, Just bought a new PSU, spent a while trying to install it..(first time)

I plugged everything in, got it to turn on for 2 seconds, kept double checking everything and it kept turning on for 2 seconds. Suddenly, it powered on for a good amount of time, and I heard it beep, I flipped the switch off in excitement ready to put everything else into my PC and boot it back on

Flipped the switch again, no response. Might I have killed my PSU by flipping it off while it was doing a good boot? Why won't it boot anymore! D: NOOOOOOOOOOOOOOOOOOOO

Yeah, I'm really sad

FUUUUUUUUUck i tried hooking up my old PSU, it's not turning on either

why were you replacing your old PSU?

I'll go ahead and assume you don't have a PSU tester. Do you have a multimeter?

Check both PSUs first before you assume the motherboard is fried. It could also be a bad connector on your motherboard.

I actually fixed it :) My dumbass was just a dumbass, it wasn't the PSU, I just unplugged some wires that weren't the PSU that weren't supposed to be replaced, but I finally figured it out.

Now the only problem is my new ATI HD4850 isn't working, I'm gonna give it one more go, if it doesn't work, I'll just RMA with Newegg. No display, no recognition for my computer. Are some motherboards non-ati compatible? I mean I read it online, but I can't confirm it

lol
i said check the wires yo.

;D