Troubleshooting
Mainly detect:
Whether the connection between control panel AP1 and compressor COMP is secure? Whether loose? Whether the connection is in correct order?
Whether the voltage input of the machine is within normal range? (Use AC voltmeter to measure the voltage between terminal L and N on the wiring board XT)
Whether the compressor coil resistance is normal? Whether the insulation of compressor coil against the copper tube is in good condition?
Whether the working loads of the machine are too high? Whether the radiation is good? 
Whether the charge volume of refrigerant is correct?
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