Yes, I'd trust J&R too. You're lucky to be that close to them.
If it weren't for the fact that your top goes up and down, I'd swear the problem is CB-1. The top should not raise with just house power, so the lift motor MUST be getting battery power somehow, which says CB-1 is OK. However, a popped CB-1 would certainly cause all your other symptoms.
This is what has led me to think some wiring has been changed.
- Jack