Service manual

Troubleshooting by Indication on the Remote Controller SiUS28-902_a
127 Troubleshooting
3.33 “LC” Outdoor Unit: Malfunction of Transmission
between Inverter and Control P.C.B.
Remote
Controller
Display
LC
Applicable
Models
RZQ18~30PVJU
Method of
Malfunction
Detection
Check the communication state between inverter P.C.B. and control P.C.B. by micro-computer.
Malfunction
Decision
Conditions
When the correct communication is not conducted in certain period.
Supposed
Causes
 Malfunction of connection between the inverter microcomputer and outdoor control
microcomputer
 Defect of outdoor unit P.C.B.
 Defect of noise filter
 External factor (Noise etc.)
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Is "E7"
displayed on the remote
controller? (not "
LC")
Disconnect the connection for
the fan motor, and turn on
again.
Replace the outdoor unit P.C.B.
(A1P).
Replace the fan motor.
Failure of the inverter
transmission occurs due to the
fan motor malfunction.
YES
YES
NO
Is the
connector for the
fan motor properly
connected to the indoor
unit P.C.B.?
Connect correctly.
NO