There are several things that could be causing your trailer brakes to no longer work but a circuit breaker in the trailer battery compartment would not be one of them as this should have no bearing on the brake output circuit if wired properly. The most obvious place to start would be by pulling each of the hubs and checking all of the mechanical components on the braking assemblies, linkages, springs, magnets, shoe lining etc.
If the braking assemblies check out which if the trailer brakes... view full answer...
I've attached the owners manual for your 4900K model which is similar to the # MA00-04500K model. It sounds like your operator mechanism is bad according to my tech contact at MaxxAir. For your 4900K model you will want the Replacement Operator Mechanism for MaxxAir MaxxFan Plus or MaxxFan Deluxe Roof Vents # MA10-20281K-1AF.
If you can't even manually lift the lid, this mechanism is definitely the issue. view full answer...
Typically when the "Auto Level Failure" error appears it's either a result of the trailer being on uneven ground or the Zero Point simply needs to be reset.
If you find that the trailer is on unlevel ground simply move it to a different location and this should hopefully resolve the issue. Otherwise you will just need to reset the Zero Point on the system, which is essentially the programmed point that the trailer will return to when using the Auto Level function.
I have attached an... view full answer...