I had just starting working at an ISP in the early days of broadband (2001-2002) when I got a call from a user with myriad, intermittent problems with his PC. Since we offered the service I asked him if he could bring the machine in and we’d take a good look at it. When he dropped it off, it was the filthiest computer system I had, and to this day have, ever seen. Multiple cigarette burns on the case front, clods of dust and hair sticking to every crevice you can imagine. It smelled bad, very bad. Plastic and metal shouldn’t stink, but this one did.
I cracked open the case and was assaulted by spiders and more dust and hair. I cleaned up these items and then realized they were nothing compared to what was on his power supply. It was greasy. I thought this odd and asked him if he had put anything on it to maybe try and lubricate the fan, anything to explain this.
Then he told me that he had noticed how hot that part of his computer would get and that he thought he could warm up Pizza slices on it. The grease had seeped into the machine and gummed up everything. How it didn’t start a fire is a marvel to me still.
I replaced the power supply and his system ran smoothly after that.