The first thing to check is the receptacle that the frig is plugged into with a volt meter. If there is not power there the problem is in the AC circuit coming from the breaker or the breaker itself is bad.Test the output side of the breaker with a volt meter. If nothing replace the breaker and retest the receptacle. If there is still no power at the receptacle you have a broken wire, highly unlikely but that is what this test checks. If that receptacle is good then it is time to check the heating element in the frig with an ohm meter. Disconnect the power and disconnect one leg of the element and test for continuity. If the element tests good you control board may have a bad fuse on it or it may be bad itself.
Eliminate the most likely first and work from there.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles