Our Bakersfield California refrigeration technician returned to a store to finish repairs on their commercial cooler. He had left the system off overnight to defrost as it had been completely iced up the day before. Diagnosed a faulty temperature control that was off calibration by 10 degrees. Replaced control. The tech also found that the TXV sensing element for the 2nd evaporator coil had gone bad. Will quote to replace the sensing element. Unit is running for now, will return.