Everything is repairable. If the repair cost is under 50% of a new unit, repair it. Someone just gave me a Danby single tower unit that didn't work. We pulled the circuit board and a transformer was shorted. $45 got a $600 unit back on line.
If you can open it up, apply 120 volts directly to the compressor and fan components, it's easy, just bypass the circuit board (which is to tried into the temp control). If it powers up then it's a board problem. If not you may have a compressor issue. In that case, take it to a local car A/C shop and they can run a test.
In your case thought, I'm guessing a circuit board issue. Compressors generally last a long tine.