Schwintek slide problem

[mikesnider]

2012 3905. Bedroom slide problem: one motor would not crank out. Worked fine prepping for trip, then failed once we arrived at camp later that same day. Schwintek Controller blinking lights indicate code 8 *HALL SIG NOT PRESENT". Manual says that means "Encoder is not providing a signal. Usually a wiring problem". Anyone experience this problem? Approach taken to diagnose it? What was the fix? Thanks fellow Volty fans. (I'd like to try fixing myself first before taking it to dealer... and risk losing the rig for ?? weeks).