I've done repairs of various systems and printers over the yrs. and believe me when it can be common at some locations to have repeat dirty systems. The best examples are concrete suppliers, factory floor, and the lone system at some guard gate. I always get the system report that the systems acts up and it never did that before, sorta thing. When you open it up, you find anything from dust bunnies, dirt build-up, coal/soot, mice dropping, pet food, cookies, ants and/or insects to include mildew and worse of all IMHO, pennies. The items kids can input to the system is boundless. Alas, the most asked question? "does my service contract cover that"? -OR-
"that's not going to cost me, right"? My favorite question, "do you have an air compressor, somewhere or an area to outside to blow it all out"?
Heck, that's my job to make people(users) happy again, until they get the bill.
-----Willy