Communication Error (Main Pcb Display Pcb) - Fujitsu AB*A30LBT Service Instruction

Trouble shooting 24
OUTDOOR UNIT Error Method:
Communication Error
(Main PCB ---> Display PCB)
Detective Actuators:
Indoor Unit Main PCB Circuit
Display PCB
Forecast of Cause:
1. Connection failure
Check Point 1-1 : Reset the power and operate
Does Error indication show again?
YES YES
Check Point 2 : Check Connection
Check connection between Main PCB and
Display PCB.
(If there is loose connector or open cable)
OK
Check Point 3 : Replace Display PCB
>> If Check Point 1, 2 do not improve the symptom, change Display PCB.
(If the symptom does not change, replace Main PCB.)
Indicate or Display:
Indoor Unit : Operation LED: OFF, Timer LED: 6 times blink,
Outdoor Unit
ERROR CODE : E : 26
Detective details:
When the Display PCB cannot receive the signal from the Main PCB.
2. External cause 3. Display PCB failure
NO
07-26
Filter LED : OFF
: No indication
4. Main PCB failure
Check Point 1-2:
Check external cause such as noise
Check the complete insulation of the grounding.
Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).