First,does the fan run ?, if the fan comes on and the compressor hums,then kicks off on the internal overload it's locked up. but, sometimes you can install whats called a hard start kit,which isn't actually a kit,it's a start capacitor with two leads that connect to the existing capactor.{if that ones not bad,usually they swell when they go bad}.I have used these on a lot of ac units and they work,I've also used them on refigerators and deep freezers,there about $15-20 bucks and available at ac supply houses.the wiring diagram is right on it,you just need the model number of your unit to get the right size.on a side note,an old timers trick is to hit it a few times HARD with a hammer while it's trying to start.that is if you have room to swing a hammer,but it may lock up again later. good luck...
