My dometic refrigator stopped working but it works good on propane not electric

Shut it off, (propane) and used compressed air to try and blow up that stack and clean out any rust that may be in there, as well as check for baffle hooked at top of stack, and hangs down inside the tube.

Try switching it to Electric only Does this solve the issue

If not you may have a bad control board

Good thinking... you need to hire a service technician (a good one!). Too many jackasses think they know these systems. Obviously, there's something wrong with the system.. if so, you need someone who knows what they're working on/with.

Check to make sure your getting 120 volts to the unit

Breaker tripped ?

sorry but have absolutley no experience with propane run refrigeration, in America never seen such a thing, please repost with another expert,

Most likely your heating element burned out or else the circuit board is bad. To test the heating element unplug it from the circuit board (j6 and j7 usually gold colored) take the two heating element wires and using an ohm meter make sure there is no resistance between them, if there is resistance the heating element is bad, Or can just put a plug onto the heating element and plug it into a 110 wall outlet and see if it gets hot. If it is not the heating element it is most likely the main circuit board. (between 1993-1996 dometic used a yellow epoxy filled circuit board that went out pretty quickly) if you have the yellow filled circuit board rather than the green one it is most likly the circuit board

Check the flu at the back is clean