Electrical? I assume you mean AC shore power.
Basic checks:
Is the trailer level? Plugged in?
Next, make sure all the circuit breakers in the converter panel are ON, also check the 12v fuse that is noted as 'refrigerator'.
Next, check the 120v plug behind the outside lower fridge vent. When on shore power, plug a circuit tester or any small lamp or appliance into that 120v plug to make sure it has power.
After the fridge has been operating for 15 minutes or so, reach in the lower vent and quickly feel for a warm to hot burner chimney.
If that chimney is warm to hot, and the trailer is level, you should have cooling in the fridge, but it can take several hours to cool the interior to 40 degrees or so, especially in hot weather.
BTW, ice packs that are placed in close proximity to the sensor inside on the 'cold plate' will 'fool' the thermostat. It may not come on until those packs are removed or placed lower in the fridge, or in the freezer.