40MBAB: Service Manual
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DIAGNOSIS AND SOLUTION (CONT.)
PC 04 - Inverter compressor drive error Diagnosis and Solution
Description: An abnormal inverter compressor drive is detected by a special detection circuit, including the communication
signal detection, voltage detection, compressor rotation speed signal detection.
Recommended parts to prepare:
• Connection wires
• IPM module board
• Outdoor fan assembly
• Compressor
• Outdoor PCB
Troubleshooting and Repair:
NOTE: For certain models, the outdoor PCB could not be removed separately. In this case, the outdoor electric control box
should be replaced as a whole.
Check the wiring between the
PCB and compressor.
Is it improperly wired?
Ensure proper connections or replace
the wires and connectors.
YES
Check the IPM.
NO
Is it functioning
properly?
Replace the IPM board or
replace the outdoor PCB.
NO
Check the outdoor fan and
the outdoor unit ventilation.
YES
Is it functioning
properly?
Please refer to “Fan
Speed Malfunction”
NO
Check the compressor
resistance values.
YES
Are they within
acceptable parameters?
Replace the compressor.
NO
Replace the outdoor PCB.
YES