Originally Posted by Ya_know
Cleaning and install maintenance kits when needed. Should include transfer roller, fuser, and pickup and feed rollers for HP products. I don't know about other brands...
Anything beyond that, I take them outside, blow them out with a little compressed air, looks for ware on gears...paper shrapnel caught in paper paths. Check paper drawers for missing or broken pieces, and test all paper paths.
Then if it's something I can't fix with any of the above, call a local certified printer repair company. Let them handle it!