I bought a EVGA 500BR 80+ PSU On my first build and it was going good for 3 days and one of the molex connectors touched a heat sink (upper left) on my ASRock B450M motherboard, and it sparked and what I thought had happened was I fried the motherboard because I had tried the paperclip test on my PSU and it seemed okay because the fan turned on. But when I pressed the power button on my case it wouldn’t turn on. So I sent that mobo back to the manufacture for a return. I have since bought a new mobo and I tried plugging in the PSU and I’m still having the same issue, I know it’s the PSU now but what’s the issue like what happened? Is there anyway I can fix it?

I ended up buying a 550w Corsair PSU And I know I’m probably going to get flak for saying that In the EVGA Forum but still, I’m waiting on it to get here. I’m just confused because when I tried the paperclip test the PSU fan turned on but when I plugged it into the board (new board) it wouldn’t power the board, no fans, no boot. And I don’t have a number read out on my board so I’m just confused.

Unfortunately, sometimes the only way to isolate a bad part in the wonderful world of electronics is to swap it out with a new or known-good part.
 
Only thing you can do is see how the Corsair unit works. 
 
Welcome to the forums, by the way..Be sure to read the Ultimate Self-Starter Thread For New Members if you haven't yet..Lots of good info there.