A number of convection microwaves are available, try Home Depot, Sears, and other appliance stores.
Our Dometic went out, but was in the 3 year Dometic warranty. We took it to a dealer and replaced it with the same model, only newer.
Fortunately, the new model worked a lot better.
Also, you might try Camping World, they have a site on line.
What is your make & model?
07 TM 40D;ISL 450 Cummins(upgraded). Very happy w/coach
Gnarly toad to scoot around.
Geocaching, hiking, fishing, National Parks, Civil War sites.