An inverter AC PCB repairing course is a training program that teaches students how to repair inverter AC PCBs. Inverter ACs are a type of air conditioner that use inverter technology to control the speed of the compressor. An inverter AC PCB repairing course is a training program that teaches students how to repair inverter AC PCBs. Inverter ACs are a type of air conditioner that use inverter technology to control the speed of the compressor.