Daikin R71FUV1 Service Manual page 385

Si20-701_B
Remote Controller Display
U4 UF
or
Applicable Models
RY-F, R(Y)-G/GA/KU/LU/NU/PU, RR-M
Method of Error Detection
Micro-computer checks if transmission between indoor
and outdoor units is normal.
Error Decision Conditions
When transmission is not carried out normally for a
certain amount of time
Supposed Causes
Wiring indoor-outdoor transmission wire is incorrect.
Defective indoor unit PCB
Defective outdoor unit PCB
External factor (Noise, etc.)
Troubleshooting
Diagnosis of incorrect or broken/disconnected wiring
If the LEDs on the indoor unit PCB are OFF, it indicates
that the transmission wiring between
indoor and outdoor units may be incorrect or broken/
disconnected.
378
Troubleshooting by Remote Controller