Getting a door back on track starts with figuring out why it left in the first place, because reseating rollers on a door that's about to repeat the problem is a waste of a visit. We check the track alignment against the jamb, check cable tension on both sides, and look at the rollers themselves - in houses from the 1980s and 90s, the original steel rollers are often still in and have worn enough to rattle loose under load.
If the cause is a loose bracket, we re-anchor it. If it's a bent section of track, that section gets swapped rather than bent back. If a cable or spring failure caused the drop, that gets replaced before the door goes back on the rail, because reseating it without fixing the root cause just sends us back out on the next call.