Intermittent (twice) Then Complete Loss of Power?

I have a Simplicity Model 950 Chairlift.

A screw worked its way out of the cover with the Status LED display and the ON/OFF switch. It caused the cover to scrape along the bottom of the rail when it would go up. It just happened yesterday but we didn't notice it when the day started because it didn't make any noise when the lift came down in the morning.

When I took the cover off, I noticed that the screw was incorrect, replaced it, and screwed the remaining two screws back down.

When I turned the switch back to the ON position, I didn't have a Status display. Thinking that I may have pulled a wire loose from the switch, I opened it all back up and reseated the connections going to the Status LED, switch, and Power ON LED . The Status LED came back on with the "-" charging indication (I have a continuous charging strip running the length of the rail.)

When I put the cover back on, the Status LED went out again. It seems that I have a loose connection but ALL of the connections are well seated. When I put a meter on the switch, I don't have a voltage drop at all. I can't find a schematic for the unit, and I don't have any instructions for disassembling the lift so I can get a better look at the circuit board.

I'm sure that I'm probably missing something pretty simple but I want to exhaust all of my options BEFORE I call for a service technician.

FYI: The batteries were replaced in February, both of the brushes that ride the charging strip were replaced about two months ago, and my charging circuit is working fine.

HELP!