Fujitsu AS G07LUCA Series Service Instruction page 72

Trouble shooting 12
INDOOR UNIT Error Method:
Indoor Room Thermistor Error
Detective Actuators:
Indoor unit controller PCB circuit
Room temperature thermistor
Forecast of Cause:
1. Connector failure connection 2. Thermistor failure
Test 1 : Check connection of Connector
Check if connector is loose or removed
Check erroneous connection
Check if thermistor cable is open
>>Reset Power when reinstalling due to removed connector or incorrect wiring.
OK
Test 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Rough value)
Temperature (°C)
Resistance Value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK
Test 3 : Check voltage of Controller PCB (DC5.0V)
Make sure circuit diagram of each indoor unit and check terminal voltage at Thermistor (DC5.0V)
Compact wall mount circuit diagram(Connector connection)
BLACK
1 1
H/E Thermistor
BLACK
2 2
CN4
BLACK
3 3
Room Temp. Thermistor
BLACK
4 4
Wall mount circuit diagram (Direct soldering to PCB)
RED
BLACK
1 1
1
CN3
2 2
2 WHITE
BLACK
3 3
BLACK
1
Room Temp. Thermistor
CN1
BLACK
2
Floor model circuit diagram (Direct soldering to PCB)
GRAY
1 1
H/E Thermistor
CN3
GRAY
2 2
BLACK
1
Room Temp. Thermistor
CN1
BLACK
2
If the voltage does not appear, replace Controller PCB and execute the check operation again.
Indicate of Display:
Indoor Unit
Operation lamp : 4 time Flash
Timer lamp : 1 time Flash
ERROR CODE : [E : 41]
Detective details:
Room temperature thermistor is open or short is detected always.
-10 0
10
58.25 33.62 20.17
Compact cassette circuit diagram (Connector connection)
Slim duct circuit diagram (Connector connection)
H/E Thermistor
3. Controller PCB failure
20 30 40
12.54 8.04 5.30
GR AY
1 1
H/E (MID
CN5
GRAY
2 2
1
CN7
2
BLACK
1 1
CN8 Room Temp. Thermistor
BLACK
2 2
Universal floor / ceiling circuit diagram (Connector connection)
BLACK GRAY
1 1
1 1
CN5
BLACK
GRAY
2 2 2 2
H/E (MID) Thermistor
1
CN7
2
BLACK
1 1
Room Temp. Thermistor
CN8
BLACK
2 2
Mini duct circuit diagram (Direct soldering to PCB)
GRAY
1 1
2 2
CN6
GRAY
3 3
1 1
Float Switch
CN9 2 2
3 3
BLACK
1 1
CN8
Room Temp. Thermistor
BLACK
2 2
02-27
Outdoor Unit
Monitor
A B C D
5 15
: Light ON : Light OFF n : n time blinking
45
4.35
) Thermistor
H/E (MID) Thermistor
E F