Curse Murphy and his ridiculous laws!!!
I am not experienced in the mechanics either, all I have experience with is recharging the AC of my car. If the connection is the same as that of a car AC input, you could buy the recharging hoses at Harbor Freight and a can of R134a and check the pressure/recharge it yourself. Might cost the same as a technician, but at least you'd then have the tools for recharging AC in the future!