Troubleshooting 12-A - Indoor Unit Error Method: Indoor Unit Number Shortage Error - Fujitsu Airstage V series Service Manual

Trouble shooting 12-A
INDOOR UNIT Error Method:
Indoor unit number shortage error
Detective Actuators:
Indoor unit Controller PCB circuit
Indoor unit Communication PCB
Forecast of Cause : 1. Indoor unit power off 2. Noise, momentary open, voltage drop
3. Communication line connection defective 4. Terminal resistor not installed / Incorrectly installed
5. Communication PCB mounting defective, Communication PCB defective 6. Controller PCB defective
Check Point 1 : Find the indoor unit that the communication is lost.
Check the service tool for missing address(s).
Perform test run mode from outdoor unit. Confirm which unit does not go into test mode.
OK
Check Point 2 : Check the indoor unit power supply
Main power ON check
Power cable connection and open check
OK
Check Point 2 : Noise, momentary open, voltage drop
Check if temporary voltage drop was not generated.
Check if momentary open was not generated.
Check if ground is connection correctly or there are no related cables near the power line.
OK
Check Point 3 : Check the communication line connection
Communication line connection, check transmission line (resistance)
and terminal connections for transmission.
OK
Check Point 4 : Check the Terminal resistor not installed / Incorrectly installed
Terminal resistor not installed check.
Incorrectly installed check.
OK
Check Point 5 : Check the communication PCB (indoor unit / outdoor unit)
Communication PCB connection check
Communication PCB check
OK
Check Point 6 : Replace Controller PCB and Communication PCB (indoor unit / outdoor unit)
Change Controller PCB and Communication PCB, and set up the original address.
Indicate or Display:
Indoor Unit : No display
Outdoor Unit : LED1 Flash, LED6 3Time Blink
ERROR CODE : No display
Detective details:
When the indoor unit number decreases for 3 minutes from
the number memorized in the outdoor units memory.
06-19-A