Troubleshooting 12 - Indoor Unit Error Method: Network Communication Error - Fujitsu Airstage V series Service Manual

Trouble shooting 12
INDOOR UNIT Error Method:
Network Communication Error
Detective Actuators:
Indoor unit Controller PCB circuit
Indoor unit Transmission PCB
Forecast of Cause : 1. Connection failure 2. Outside cause 3. Transmission PCB failure 4. Controller PCB failure
Check Point 1 : Check the connection
After turning off the power, check and correct followings.
p Is Indoor Transmission PCB loose?
p Check loose or removed connection of communication line between Indoor
and Outdoor unit.
p Make sure Terminator (CN22) is located at Controller PCB of Main Unit.
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 Transmission PCB and Controller PCB
p If some of Indoor units have errors, replace Transmission PCB of the Indoor units that have the error.
>>If the symptom does not change, replace Indoor unit Controller PCB.
p If all the Indoor units have error, check if the Outdoor Unit Transmission PCB has a loose connection (Refer to Trouble Shooting 45).
>>If the symptom does not change, replace Outdoor unit Transmission PCB (Replace Controller PCB if it does not change).
Note : Communication error factor
1)System design (Wiring length or connection
number over)
2)Mis-install (Address setting,Terminal resister,
Disconnection, Ground wire)
3)No power (Include a signal amplifier and turn
on all power supplies.)
Indicate or Display:
Indoor Unit : Operation LED Flash, Timer LED 5 Times Blink
Outdoor Unit : LED1 Flash, LED6
ERROR CODE : E : 1F
Detective details:
When the cut-off of network communication is detected (more than 90 seconds
passed since the last receipt of Outdoor unit signal).
06-19
Swing LED 1 Time Blink
1Time Blink
Master Unit Schematic(CN22:TERMINATOR)
Note : Terminator
Terminator is a resistance that prevents the
reflection of the signal at the end terminal of
the circuit which causes abnormal data
transmission when connecting multiple
devices with 1 piece of cable.