No power to slides, awnings or jacks

[Otiss]

Kind of the same issue as Charlie mentioned, winterizing my 34' Cougar and I smelled something like hot plastic. Now none of the slide outs, awning or front jacks work. Should I hear my inverter fan running? Thanks everyone. I have the battery in at my local auto parts store getting tested, but I'm not very confident it's a battery issue. Just got back from a 10 day trip and everything work fine. The microwave still powers up.
I should add that nothing works with the battery or on shore power now. TY

[sourdough]

First things first. You said the microwave works then said "nothing works with the battery or on shore power now"; what exactly doesn't work? There are 2 power sources; the battery(s) and shore power. The converter provides d/c to the batteries. That burning smell could be most anything but sounds like something electrical.

Do you have a multimeter and know how to use it? Are you comfortable working on electrical? When you were winterizing and smelled this were you inside or outside? Start at the power ped and make sure nothing is melted there and you have the correct voltage(s). Go to the power center (breakers/fuses) and open it up; put your nose up close and see if you smell anything, electrically burned parts smell a while. If so open it up and see what you have. Then we can go from there.