Service Manual

8. Troubleshooting
187
SMGB0079 rev.0 - 01/2013
8
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
The Comp. does not
stop or start even if the
setting temperature on
the LCD changes to *3)
Failure of air inlet
thermistor
Failure of thermistor
Check it by self-checking *2)
Replace or correctly connect
the wires if Abnormal Operation
exists
Disconnection of
thermistor
Abnormal operation of the remote control switch
cord
Failure of the indoor unit PCB
Check PCB by means of the
self-check mode *1)
Replace PCB if it failed
Incorrect optional setting
Check the setting condition of
“remote control thermostat” by
means of the optional setting
Setting and control:
“00”: Control by means of the
indoor thermistor for the suc-
tion air
“01”: Control by means of the
thermostat of the remote con-
trol switch
“02”: Control by means of the
average value of the indoor
thermistor for the suction air
and the thermostat of the re-
mote control switch
If the thermostat of the remote
control switch is not used, set
at “00”
Incorrect Input/Output setting
Check setting condition of “i1”
and “i2” by Input/Output setting.
* Setting and Control:
“01”: Room thermostat (Cooling)
“02”: Room thermostat (Heat-
ing)
In case that room thermostat is
not used, set for input signal ac-
tually used. If no signal is used,
set at “00”
Indoor fan speed does
not change
Failure of the Discharge
Air Temp. Thermistor
Failure of the Thermis-
tor
Check the Thermistor by
means of the self-check mode
*2)
Replace or Correctly connect
the wiring when it is abnormal
Disconnected Wire of
the Thermistor
Failure of the Remote Control Switch
Check it by means of the self-
check mode *1)
Replace if it failed
Failure of PCB for the indoor unit Replace if PCB fails
No defrost operation
mode is available dur-
ing the heating process
or the defrost operation
continues
Failure of thermistor
for outdoor evaporating
temp. during heating
Failure of thermistor
Replace or correctly connect when it is abnormal
Disconnected wire of
thermistor
Failure of 4-way valve
Disconnected 4-way
valve coil
Measure the resistance of coil
Replace the 4-way valve
Incorrect activation of
4-way valve
Enforced power supply
Disconnected control wires between indoor unit
and outdoor unit
Check the connectors Correctly connect the wiring
Failure of the outdoor
units of PCB
Disconnected wiring
to PCB
Check the connectors Correctly connect the wiring
Failure of PCB
Check PCB by means of the
self-check mode *1)
Replace PCB when the check
mode is not available
Failure of the Indoor
Unit of PCB
Disconnected wiring
to PCB
Check the connectors Correctly connect the wiring
Failure of the PCB
Check PCB by means of the
self-check mode *1)
Replace if PCB fails
The LED and the LCD
on the remote control
switch remain ON
Failure of PCB in the indoor unit or the remote
control switch