Fujitsu ASU18RLF Service Manual

1. Connector failure connection
2. Thermistor failure
3. Controller PCB failure
Test 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Rough value)
If Thermistor is either open or shorted, replace it and reset the power.
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
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)
If the voltage does not appear, replace Controller PCB and execute the check operation again.
Compact wall mount circuit diagram(Connector connection)
H/E (MID) Thermistor
Room Temp. Thermistor
Room Temp. Thermistor
H/E Thermistor
Compact cassette circuit diagram (Connector connection)
Wall mount circuit diagram (Direct soldering to PCB)
Slim duct circuit diagram (Connector connection)
BLACK
BLACK
3
4
CN4
1
2
3
4
1
2
BLACK
BLACK
BLACK
BLACK
BLACK
BLACK
1
2
1
2
CN3
CN1
1
2
3
1
2
3
RED
WHITE
H/E Thermistor
Room Temp. Thermistor
BLACK
BLACK
1
2
1
2
11
22
CN5
CN8
GRAY
GRAY
1
2
CN7
BLACK
BLACK
1
2
1
2
11
22
CN5
CN8
GRAY
GRAY
H/E (MID) Thermistor
Room Temp. Thermistor
Floor circuit diagram (Connector connection and Direct soldering to PCB)
BLACK
BLACK
1
2
1
2
1
2
CN3
CN1
GRAY
GRAY
H/E (MID) Thermistor
Room Temp. Thermistor
Trouble shooting 8
INDOOR UNIT Error Method:
Indoor Room Thermistor Error
Indoor unit controller PCB circuit
Room temperature thermistor
Room temperature thermistor is open or short is detected always.
Detective Actuators:
Detective details:
Indicate of Display:
Forecast of Cause:
02-12
4.35
113
5.308.0412.5420.1733.6258.25
Resistance Value
(k )
104866850
32
4540302010
0
14
-10
Temperature (°F)
Temperature (°C)
Indoor Unit
Outdoor Unit
Operation lamp : 4 time Flash
ERROR CODE : [E : 41]
Timer lamp: 1 time Flash
Monitor
ABCDEF
: Light ON : Light OFF n : n time blinking

Fujitsu ASU18RLF Specifications

General

Brand	Fujitsu
Model	ASU18RLF
Category	Air Conditioner
Language	English