I have a 2019 3791RD and just replaced a slide motor on our door side rear slide (living room). The motor itself was fine, but the wiring had been twisted so much that it had pulled from the circuit board on the motor. Apparently the motor wasn't properly seated on the "H Column" which allowed the motor to turn without running the slide in or out. It started as an intermittent problem, then the slide just quit. It was an easy fix once I found what the problem was. I still have the old motor and will try to re-solder the wiring harness onto the circuit board so I can keep it as a spare.
Schwintek slide system is really very simple, so I can't imagine why yours would need to be "rebuilt". If the "H Column" wasn't installed properly, it may need to be removed and replaced, but that would be a factory installation issue.
Take a look at "MY RV Works" on You Tube. He has some great videos about how Schwintek slides work and how to fix most issues with them. He's a mobile tech in the north east. Really informative channel.
https://www.youtube.com/channel/UCoK...ZLCD3flLXZVQvw