Gree GMV-VQ680WM/C-X Service Manual page 114

Gree
Between the Primary Controller
Whether the communication
cables between the main board of outdoor
unit and inverter fan drive board
The main control board may be
2.33 "C4" Indoor Unit Loss Fault
Fault display: main board of outdoor unit, wired controller of indoor unit and receiver of indoor unit
display
Fault diagnosis:
When the unit identifies that more than three indoor units are disconnected, it will stop for protection.
Possible causes:
■ Poor contact of communication cables;
■ The indoor units are powered off;
■ The main board of indoor unit operates improperly.
Troubleshooting:
"C3" Communication Fault
and Inverter Fan Driver
are connected properly?
Yes
Whether the outdoor unit's
fan drive board is normal?
Yes
abnormal
GMV6 HR DC Inverter VRF Units Service Manual
No
Connect the communication
No
Replace the fan drive board
Yes
Replace the main control board
112
cables properly