Fujitsu AB F18LAT Series Service Instruction page 52

Trouble shooting 18
OUTDOOR UNIT Error Method:
INDOOR UNIT
Outdoor unit computer
communication error
Detective Actuators:
Outdoor Unit Main PCB Circuit
Forecast of Cause :
1. Main PCB failure
Check Point 1 : Replace Main PCB
Change Main PCB.
Trouble shooting 19
INDOOR UNIT Error Method:
INDOOR UNIT
Indoor manual auto switch error
Detective Actuators:
Indoor Unit Controller PCB Circuit
Forced auto switch
Forecast of Cause :
1. Forced auto switch failure
Check Point 1 : Check the Forced auto switch
Check if Forced auto switch is kept pressed.
Check ON/OFF switching operation by using a meter.
>>If Forced auto switch is detective, replace it.
OK OK
Check Point 2 : Replace Controller PCB
If Check Point 1 do not improve the symptom, change Controller PCB.
Indicate or Display:
Outdoor Unit : No indication
ERROR CODE : E : 1c
Detective details:
When it cannot receive an effective signal for 10sec between
the Main CPU and Sub CPU in outdoor unit.
Indicate or Display:
Outdoor Unit : No indication
ERROR CODE : E : 20
Detective details:
When the Forced auto switch becomes ON for 30 consecutive seconds.
2.Controller PCB failure
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