5.25 inch floppy drive inspection, repair, cleaning, alignment
In this video I show the kind of actions it usually takes to repair a random 5.25 inch floppy drive that was sold as non-functional.
This particular drive had a nice variety of issues that were quite easily fixed within an afternoon. This certainly isn't always the case. Some take even less effort. Others take days effort. Of course, this is highly dependent on the kind of issues the particular drive has.