does the contactor pull in? if not, can you manually push in the contactor? (it may have a cover over the contactor; that's to prevent ants from coming in and nesting. this cover can be removed by two screws.) if you can and the unit comes on; the compressor and the fan, then you know the capacitor is good. I believe you said you have 240v at the line side of the contactor. if you push it in and it does not come on, check to make sure you have 240 on the load side. I had to replace my contactor on my one year old unit a few weeks ago. unsual but not unheard of. do yo have 24v at the contactor. if not, it's possible that you have a low pressure cut out switch and the unit has a low charge. I'm not in front of the unit but these are the things I do to diagnose.
any more questions, please post.
perhaps a little more pleasant tone would be appreciated.