The constant temperature and humidity tester does not move when the power is turned on → the phase is missing The power supply is abnormal → check the power supply No output from the controller → check if the PC board of the controller works Control power supply insurance burned out → check the reason to replace the insurance Malfunction of safety protection device → check safety protection measures and manually reset Can't cool down or slow down → refrigeration compressor is broken (update or repair) Refrigerant leakage → notify the manufacturer of the constant temperature and humidity tester or ask a professional to repair Yunfeng motor does not rotate or reverse → check the cause or update The electromagnetic switch of the compressor is broken → Check the cause update Sticky dust on condenser → blow off with high-pressure air nozzle Poor heat dissipation of the unit → poor installation location, reposition and install patent pencil Tonglu shangmei pen industry co.,ltd , https://www.shangmeipenindustry.com