Rust + Weird Fan Quirk
Hi, I haven't been the nicest to my Prusa Mini and so it has rust (maybe just surface?) on both the sensor and the extruder. I wonder if this is a good enough reason to replace my old extruder with something like the Slice's Prusa MINI Upgrade Kit. Another issue I have been having is that the fan will make this like weird "creeking?" noise that sounds like it wants to die before chilling out. Idk why it does this, it didn't do this before.
RE: Rust + Weird Fan Quirk
Check if there is no rust or oxidation inside of the nozzle and the heatbreak.
The same for the areas where hot elements touch each other like the heatbreak and the radiator, thermistor/heatbreak holes.
If it prints there is no need to replace it, they tend to change color over time due to fingerprints or leftovers from manufacturing processes.
Replacing stock kit to Slice Engineering kit will improve overall print quality because it has some additional features auch as better heatbreak design and coated copper head which withstands hardened nozzles better in the threaded section ( standard kit aluminium is very soft).
Fans sometimes can be fixed by removing that centered sticker and pouring a drop of machine oil, and putting the sticker back in the place. Oil viscosity should help to increase a friction just a bit and thus prevent rattling.
See my GitHub and printables.com for some 3d stuff that you may like.