Pc sparked and smoked, any help?

Oct 14, 2018
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My friend gave me a pc and I wanted to see how it looked in the inside when it was on. I opened it up and there was a wire that wasn’t connected to anything, but the pc was working just fine. So I got to see what it looks like and decided to start closing it back up, the wire that wasn’t connected hit a part of the motherboard at the bottom of it and it sparked and smoked a little and then it shut off the pc all the way. I tried turning it back on and it can’t. Any help telling me if it’s the power supply that burnt out or is it the motherboard? Power supply is a 600w and the motherboard is a (gigabyte AB359 - Gaming 3).
 
Oct 14, 2018
2
0
10
The wire does run from the power supply, it’s a extra wire that could go into something else. It’s a 4 pin power cord, there’s a small one and a bigger one connected to one whole wire. It is yellow, black (2 black ones), and a red one all in one.