Maintenance and Repair: After powering on for 20 seconds, the compressor overheated and the overcurrent protector tripped. The air conditioner casing was dismantled, and with the power off, the start capacitor charge-discharge function was measured as good; the overheat and overcurrent protector were also found to be in good condition. The resistance of the three wiring terminals of the compressor was measured, and it was confirmed that the main winding (M) plus the auxiliary winding (S) equals the common winding (C), which is normal. A suspicion arose that the compressor might be jammed. Calling the Beijing Midea Air Conditioner After-sales Service Hotline, the following solution was adopted: tilting the air conditioner unit 45 degrees forward/backward and left/right, then turning it on and using a wooden hammer to tap the lower half of the compressor, causing the jammed internal parts to vibrate and begin operating. Considering the failure of the air conditioner's compressor not starting could be due to the unit being stored for too long, leaving the piston assembly stationary in one position and unable to rotate. Additionally, the higher viscosity of refrigerating oil in winter is another possible reason. Using the wooden hammer tapping method can resolve the fault. The Midea air conditioner did not start its compressor after being placed unused for two years.
Source: Beijing Midea Air Conditioner Repair Center http://blog.163.com/midea_ktwx.