Midea V8 VRF Series Service Manual page 75

V8 VRF Indoor Units
6.1.27 C79 - Abnormal communication between the IDU main control board and adapter board
Error display
Faulty IDU: The fan continues running, and the EXV is closed. Other IDUs of the same system: operate
Error impact normally.
ODU of the same system: operate normally.
Error trigger If the main control board of an IDU has lost communication with the adapter board for 2 min
Error recovery
Automatic recovery
Possible cause
See the Troubleshooting section.
Troubleshooting
74
Digital display
Cause 1: The communication
cable between the main control
board of the IDU and the adapter
board has become disconnected
Cause 2: The communication
cable between the main control
board of the IDU and the adapter
board has become loose or is
connected to a wrong port
C79
Cause 3: The IDU main control
Cause 4: The adapter board is
Display position
Panel, display box, and wired controller
or short circuited
board is damaged
damaged
Replace the
communication cable
and properly connect
the cable
Properly connect the
cables and ensure
they are connected to
the right ports
Replace the main
control board of the
IDU
Replace the adapter
board