1 system A/C preventative maintenance check complete. Upstairs system. Left replacement filters. Tested mechanical and electrical components. Found no in line water safety to protect the furnace from water damage. Found burning on the main electrical switch. Found weak capacitor. Found low refrigerant levels. The system has no hard start kit. The system has no surge protection. Replaced main electrical switch. Replaced capacitor. Installed hard start kit. Recharged the system with 3 lbs R410A. Chemically washed condenser coil. The system is cooling at this time.