I've not dug about in one for years but you should be able to get the connection off the the compressor and test the windings with a multimeter. You should have 3 terminals. A neutral which joins start and run to common point and a start terminal and run terminal. The start winding will have a resistance of something like 20 ohms measured from common to the start and the run something like 40 ohms between common and start. It's been so long I can't remember the resistance ranges exactly but its something in that range. Overr the start and run you will get the total of both, so on my guesstimates 60 ohms. Messing about with a meter for couple of mins you will be able to find common, start and run terminal arrangement. Also check insulation to earth but guessing this is OK otherwise fuse would blow or cct trip. If compressors goosed and you havent got an earth fault then you would find an open circuit between common and either start or run winding. If its compressor or loss of refrigerant its not worth the hassle to repair I'd say. If compressor is OK then worth a go.