I, no kidding, had a PC once that booted up better if opened up the side and pointed a space heater directly into it. On cold starts it would boot, then lose a

I, no kidding, had a PC once that booted up better if opened up the side and pointed a space heater directly into it. On cold starts it would boot, then lose all power seconds later, boot again, and it would work for a few seconds longer than before, rinse and repeat 5 times or so and it would finally stay booted. After surmising that it was temperature related, I decided to try applying extra heat. It worked. After it was running for 2 or 3 minutes I would turn the heater off. I never identified what component was causing this.