Check The Connection; Check If Any Outside Cause Such As Voltage Drop Or Noise; Check Communication Pcb And Controller Pcb - Fujitsu Airstage V-II Service Manual

Trouble shooting 12
INDOOR UNIT Error Method:
Network Communication Error
Detective Actuators:
Indoor unit Controller PCB circuit
Indoor unit Communication PCB
Forecast of Cause : 1. Connection failure 2. Outside cause 3. Communication PCB failure 4. Controller PCB failure
Check Point 1 : Check the connection
After turning off the power, check and correct followings.
Is Indoor Communication PCB loose?
Check loose or removed connection of communication line between Indoor
and Outdoor unit.
When the signal amplifier is connected , is it failure of signal amplifier?
(Refer to "TROUBLE SHOOTING FOR OPTIONAL PARTS")
OK
Check Point 2 : Check if any outside cause such as voltage drop or noise
Instant voltage drop ----- Check if there is any electric equipment with a large load within the same circuit.
Momentary power failure ----- Check contact failure or leak current in power supply circuit
>>Check Outdoor Unit as well.
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). And check the complete insulation of grounding.
>>If the same symptom does not reappear after resetting the power, possibility of noise is high.
OK
Check Point 3 : Check Communication PCB and Controller PCB
If some of Indoor units have errors, replace Communication PCB of the Indoor units that have the error.
>>If the symptom does not change, replace Indoor unit Controller PCB. (Refer to 06-03 page Main PCB removal.)
If all the Indoor units have error, check if the Outdoor Unit Communication PCB has a loose connection (Refer to Trouble Shooting 15).
>>If the symptom does not change, replace Outdoor unit Communication PCB (Replace Controller PCB if it does not change).
Indicate or Display:
Outdoor Unit : E.5 U.1
Indoor Unit : Operation LED 1 times Flash, Timer LED 6 Times Flash,
Filter LED Continuous Flash.
Error Code : 1 4
Detective details:
When the cut-off of network communication is detected (more than 90 seconds
passed since the last receipt of Outdoor unit signal).
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