Service manual

SiUS28-902_a Troubleshooting by Indication on the Centralized Remote Controller
Troubleshooting 146
4.3 “M8” Malfunction of Transmission between Optional
Controllers for Centralized Control
Remote
Controller
Display
M8
Applicable
Models
Centralized remote controller
Method of
Malfunction
Detection
Malfunction
Decision
Conditions
Supposed
Causes
 Malfunction of transmission between optional controllers for centralized control
 Defect of P.C.B. of optional controllers for centralized control
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Is
transmission wiring
disconnected or wired
incorrectly?
The P.C.B. of one of the optional
controllers for centralized control is
defective. Try turning on/off using
each optional controllers for
centralized control, and replace the
P.C.B. of the one that is unable to
control the indoor unit.
NO
NO
Fix the wiring correctly.
YES
YES
Has a once
connected optional
controller for centralized
control been disconnected
or its address
changed?
Turn on power supply for all
optional controllers for centralized
control.
Reset power supply simultaneously
for all optional controllers for
centralized control.
YES
NO
Is
the power supply
turned on for all optional
controllers for
centralized
control?
Set reset switch to "normal."
YES
NO
Is
the reset switch
of all optional controllers
for centralized control set
to ''normal?''