Arrived on site to preform a 3 system maintenance. Indoor; changed filters and cleared drain line. Checked electrical connections, amp draw and capacitance. Upstairs unit has a capacitor reading low. Outside; cleaned condenser coil and checked refrigerant pressures, found basement system low on charge. Checked electrical connections, amp draw and capacitance. Found a refrigerant leak in the basement level evaporator coil. Recommend replacement.