here's the deal. 20 yr. old apt. style (in the wall) air handler with water dripping past the pan under slant coil. pan not leaking, charge and air flow correct (according to tech). they had about five of these and after checking and good cleaning, all but two have quit. those two were cleaned again. still dripping. tech says the aluminum fins have broken down to the point that water is clinging instead of running to the pan and is calling for coil replacement. what do you think? First co. ah.