Responded to a no cooling call in Boston, MA this week. Upon inspection, discovered frozen evaporator coils on the Carrier 25HBC5 air handler. Performed static pressure checks which revealed high external static pressure at 0.9" WC, likely due to dirty air filters. Changed filters and performed complete air flow inspection. Evaporator coil had also lost charge. Evacuated remaining refrigerant, replaced filter drier, and recharged with 7 lbs of R-410A to factory specifications. Cycle tested, ensuring proper superheat/subcooling. Customer now enjoying 20°F temperature split and cool, dehumidified air flow throughout home.