Service manual

Troubleshooting by Indication on the Unified ON/OFF Controller SiUS28-902_a
151 Troubleshooting
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Is the
power supply for
the indoor unit displaying
a malfunction
turned
on?
Is
transmission wiring
disconnected or wired
incorrectly?
Is the
transmission
wiring with the master
controller disconnected or
wired incorrectly?
Is the
master
controller's connector for
setting master controller
disconnected.
Set the group No.
correctly.
Replace the indoor unit P.C.B.
Fix the wiring correctly.
Fix the wiring correctly.
Connect the connector
correctly.
Replace the central P.C.B.
Reset power supply for all
optional controllers for
centralized control
simultaneously.
NO
YES
NO
YES
YES
NO
YES
Turn the power supply of the
indoor unit on.
YES
NO
NO
YES
NO
YES
NO
Has a
once connected
indoor unit been removed
or its address
changed?
Diagnose the cause with the
air conditioner's failure
diagnosis manual.
NO
YES
Is a
malfunction
code displayed on the
remote controller?
Is
the group
No. of malfunctioning
indoor units
set?
Is
transmission
with all indoor units
malfunctioning?