Look at THIS and let us know if you checked the "indoor" (evaporator) coil as well as the "outdoor" (condenser) coil and found it's CLEAN as well. If the evap isn't clean and/or condensate not draining, it'll freeze.
If you find the compressor is not starting, could be the Capacitor. There are modern inexpensive multimeters that'll test uF capacitance.
If it starts and runs hot, could be it's running tight and overheating. Again, inexpensive clamp-on AC ammeter can tell you if its draw matches the label plate on the compressor.
I don't know if one can start then run hot because of a failed capacitor. I don't think so, but not really sure.