Damon makes a good motor home. And yours is old enough that the Common Problems like screws they forgot to tighten should NOT be an issue as they should already have been fixed... So now you are into two sets of problems
Common maintenance like roof caulking and tire changes often ignored by prior owners.. and Wear out/break, and since almost NOTHING inside that RV is "Damon" this too is common to all other Motor homes.
If you do not have the "Owner's information package" (about 5-10 pounds of owners manuals in a zippered pouch) find the makes and models of all your appliances. . Water heater, Fridge, Furnace A/C Slideouts, Even the door and wondows have owner's manuals but .> Well you can skip those.. MIrrors and such
Google Make, Model, manual
THt is if it's a DOmitic 9212 Microwae you would google: dometic 9121 manual
NOTE: Dometic does NOT make microwaves so you may not find that one.. but the product ID label (open the door) on mine identifies it as an LG (Lousy goods) #### and sure enough it did not work when it was newe.. I re-engineered a couple things, replaced one LG part with a nearly but not quite identical GE part and now it works fine.
Store the PDF of the manuals on ye-old-hard-drive.