Indoor Unit Number Shortage Error - Fujitsu Airstage V-II Service Manual

Trouble shooting 62-2
INDOOR UNIT Error Method:

Indoor unit number shortage error

Detective Actuators:
Indoor unit Controller PCB circuit
Indoor unit Communication PCB
1. Indoor unit power off 2. Noise, momentary open, voltage drop
Forecast of Cause :
3. Communication line connection defective 4. Terminal resistor setting mistake
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 system drawing and service tool.
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, open check
OK
Check Point 4 : Check the Terminal resistor setting
T erminal resistor setting 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 Main PCB and Communication PCB (indoor unit / outdoor unit)
Change Main PCB and Communication PCB, and set up the original address.
(Refer to 06-03 page Main PCB removal.)
Indicate or Display:
Outdoor Unit : E.1 4.5
Indoor Unit : No display
Error Code : No display
Detective details:
When the indoor unit number decreases for 180 seconds from the memorized
maximum indoor units number after power(Breaker) ON.
04-69(02)
Attention!!
Even if this error occurs, system does not stop.
If the failure indoor unit is pinpointed and
it needs to erase the error indication,
it can be reset by function setting
(F3-41: Maximum memorized indoor unit
number reset).