So one of my parents friends needed their pc fixed (it wasn’t turning on), I told them I could take a look. I pop open the side panel and there’s just a thick layer of dust over everything. I took it apart, cleaned out the dust and the realized there was no exhaust fan. It was a Lenovo pre-built. How do you sell a pc without an exhaust fan? The only fan in the whole system was the CPU cooler that had like an 80mm fan on it! Turns out front panel connectors had come slightly undone, so I was able to get it working, but it’s just so dumb that a large company like Lenovo would do that. 
 

System specs for the Lenovo weren’t so great, so I’m sure it wouldn’t have overheated but still...