I was at a LAN party in the early 2000s where an attendee brought a computer that would run just long enough to start Windows, then immediately do a hard reset. He swore it worked perfectly before leaving home.
One side of the CPU cooler had come lose as he was moving his PC between home and the venue, although we didn't discover that until after we had run extension cords from another room to keep from overloading the breaker for the circuit in the main area.
LAN parties are one thing I will always miss about that era. There's something about sitting around a plastic folding table playing games with your friends that you don't get from logging onto an online game.