Welcome to the forum!
We're sorry that it took your having a problem to join us, but we hope that you will stay engaged after you have a resolution.
You said that you took it to a dealer. Was this the same dealer that you bought it from? Was it a dealer that handles that line of RVs?
Have you searched youtube looking for videos for you model?
Have you tried customer service for your unit for advice or maybe they can suggest a dealer that can help you?