Troubleshooting for SA Indoor Unit
SiBE121123_A
175
Service Diagnosis
6.7
Signal Transmission Error (between Indoor Unit and
Remote Controller)
Error Code
U5
Method of Error
Detection
In case of controlling with 2 remote controllers, check the system using microcomputer if signal
transmission between indoor unit and remote controller (main and sub) is normal.
Error Decision
Conditions
Normal transmission does not continue for specified period.
Supposed
Causes
Connection of 2 main remote controllers (when using 2 remote controllers)
Defective indoor unit PCB
Defective remote controller PCB
Transmission error caused by noise
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Is SS1 of
both remote controllers
set to "MAIN"?
Do all indoor
PCB microcomputer
monitors blink?
Does
operation return
to normal when the
power is turned off
momentarily?
NO
NO
NO
YES
NO
Replace the indoor unit
PCB.
Set one remote controller to
"SUB"; turn the power supply
off once and then back on.
There is possibility of
malfunction caused by noise.
Check the surrounding area
and turn on again.
There is possibility of
malfunction caused by noise.
Check the surrounding area
and turn on again.
Normal
Normal
NO
NO
Using
2 remote controllers?
YES
YES
YES
Replace the remote controller.
Return to normal?
Return to normal?
YES
Replace the indoor unit PCB.
YES
(R13276)
