Midea M-Thermal Series Service Manual page 56

4.10 H1 Troubleshooting
Digital display output
Description
 Communication error between outdoor unit main control board and inverter module.
 M‐Thermal Split stops running.
 Error code is displayed on outdoor unit main PCB and user interface.
Possible causes
 Power supply abnormal.
 Interference from a source of electromagnetic radiation.
 Outdoor unit main PCB or inverter driven module damaged.
Procedure
LED on the main control board of
outdoor unit and inverter module are
Communicatin wires between the main
control board of outdoor unit and
inverter module is loose
There is a source of electromagnetic
radiation near the unit, such as
high‐frequency transmitter or other high
strength radiation device
Replace outdoor unit main PCB and
inverter driven module in turn
201909 55
H1
light
No
No
No
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LED is not light, the board is
Yes
damaged,or have short circuit
Yes
Reconnect the communicatin wires
Yes
Remove the source of interference
M‐Thermal Split