Back when I worked at BestBuy's Geek Squad (Counter Intelligence Agent) this contractor dude came in on his lunch break with his personal gaming rig, some Dell tower with all the bells and whistles of the time.
He said that after he soundproofed it (wut?) it worked for three hours and then quit on him. According to him it would try to post, beep a few times, and then conk out.
So I popped 'er open... to find that his "soundproofing" solution was to fill the damn chassis with expansion foam.
The poor PC cooked itself with its own heat. Not even a Dell deserved that fate.