Jimmy,
When was the last time you did some maintenance on the unit? If it has a self-contained compressor, monthly vacuming out of the dust that accumulates in the fan can keep your refrigeration units running better and with less service calls.
How old is the unit and is it still maintaining proper temperature? (35 degrees–or less)
The problems you are having can happen any time of the year, but in the heat of the summer, when compressors must work over-time, if they haven’t been maintained, they will start to break down.
Moisture accumulation inside the box is a sign that the compressor isn’t doing its job.