The GREE 301387101 Main Control Board is an electronic replacement component designed for compatible GREE HVAC equipment, including packaged terminal air conditioners (PTACs) and heat pump systems. It functions as the system’s central controller, processing signals from temperature sensors and coordinating essential operations such as compressor cycling, fan control, and heating and c... https://www.partshnc.com/301387101-gree-main-control-board