I built my PC about a month or so again, and after some initial PSU problems, it's been working perfectly. However, after installing a network card two days ago, things started to go wrong. It shut off once, randomly, that night, and twice yesterday before it completely failed altogether.
The first time it shut down yesterday, I removed the network card, but that didn't fix the problem. The PSU also passes the paperclip test (although I realize that has limitations), so I've been assuming the problem to be with the mobo.
Also, there don't seem to be any loose connections, and nothing seems to be touching the motherboard itself. Is my mobo shot, or does anyone have any ideas?
I didn't find the right solution from the Internet.