You got a lot of useful information here.
My 13 month old Dometic gave out and had to be replaced. I talked to Dometic and they extended the warranty BUT I had to have it repaired at a approved shop. Well I tried finding one and after a long search the two local places one was a 6 month wait and the others reviews were absolutely horrible.
I bought a replacement on eBay and my brother friend and I replaced it ourselves. The hardest part is getting the units on and off the roof.
I hope the repairs suggested work out for you!
Safe and happy travels!
Dave