The fridge's AC circuit breaker is the first thing I'd check. But other than that your issue could be a couple of things. The electric heating element could have failed. Or perhaps there's an issue with the fridge's control board.
Rather than just replace things... I'd get a tech to run some diagnostics on everything.
__________________
2017 Winnebago Adventurer 37F
2016 Lincoln MKX Toad