Diagnosed that the upstairs zone damper is failing intermittently and not opening when called to do so. I removed the damper from the zone system and placed it in the open position so the upstairs will have cool air. Customer chose to have the damper and the zone board replaced. Parts will be ordered and we will return to complete repairs once received. Installed one new 14” round zone damper into upstairs supply run and also replaced a two-zone control board. I then tested operation of system insuring both dampers opened and closed and were functioning properly. I programmed zone board to match system specifications. System is operational at this time.