I run a PC repair side hustle and a customer brought in his home computer claiming he didn't really know why it wasn't turning on but he suspected the PSU.
The stench of tobacco smoke and nicotine was pervasive but even still it didn't prepare me for what I'd find inside. Ended up replacing the case completely as well as a new PSU and cooler (opted for the AXP90 X47 by Thermalright since the previous one wasn't even really mounted properly) but I did clean up the rest of the components as best as I could.
Enjoy the before and after pics of the process.