Completed a/c maintenance on 5 central a/c systems. All of the condensers were shut off at the disconnect when restoring power the master bedroom system was flashing an error code of ch 60. Diagnosed issue with tech support and neno d to replace main pcb control board and fan motor at the condenser. Chemically cleaned all evaporator coil’s. Inspected blower compartment and primary drain pan. Treated and cleared all drain lines,traps and tested all condensate pumps. Replaced all air filters 16x20x4 20x25x4 14x30x1 14x25x1 12x24x1 Brushed and cleaned all electrical cabinets and tighten and secured all electrical connections on both inside and outdoor units. Tested all safety switches all in working condition. Chemically cleaned outdoor condenser and checked operations and refrigerant pressures. Tested all electrical voltage, capacitors, and amperage on all motors and compressors. Master bedroom system is currently down need to replace control board and fan motor on condenser. View