Article source: Beijing Midea Air Conditioning Repair http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3760772.
Warm reminder: For compressor shaft seizure, after connecting the power supply, you can gently tap the shell of the compressor with a wooden hammer or rubber hammer and constantly change the tapping position; or use a voltage regulator to appropriately increase the power voltage; or increase the starting capacitor capacity. This method generally can eliminate minor shaft seizure (cylinder jamming) faults.
Repair method: Replace the compressor, test machine normal operation.
Midea KFR-75LWD air conditioner does not cool, shows E04
Analysis and detection: After the compressor starts, use a clamp meter to detect the current, which quickly rises to 35A, then stops. After 3 minutes, the compressor starts again, and after this happens 4 times, the machine displays the E04 code. Checking the electronic control system reveals no fault, checking the AC contactor and compressor capacitor also reveals no fault, so it is judged that there is a compressor fault. The resistance of the compressor coil is measured as normal, thus it is judged that the compressor has seized shaft (cylinder jam). Increasing the start-up capacitor by 2 times fails to drive it successfully, then using phase wires connected to the C"； and R terminals, strong start-up is attempted but still ineffective.