Fujitsu Airstage V series - Troubleshooting 11 - Indoor Unit Error Method: Communication Error between Controller PCB and Transmission PCB

Trouble shooting 11
INDOOR UNIT Error Method:
Communication Error between
Controller PCB and Transmission PCB
Indicate or Display:
Indoor Unit : Operation LED Flash, Timer LED 6 Times Blink
Swing LED OFF
Outdoor Unit : LED1 Flash, LED6 1Time Blink
ERROR CODE : E : 21
Detective Actuators:
Indoor unit Controller PCB circuit
Indoor unit Transmission PCB
Detective details:
When Parallel communication error (Transmission reset occurs continuously
more than specified times) is detected.
Check Point 3 : Replace Transmission PCB
Replace Transmission PCB (If the symptom does not
change, replace Controller PCB and set up the original
address.
Check Point 1-2 : Check outside cause such as noise
p Check the complete insulation of the grounding.
p 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).
Check Point 1-1 : Reset the power
Check Point 2 : Check Connection
YES
NO
Does LED error indication reappear?
p Check if Indoor Transmission PCB is removed.
OK
Forecast of Cause : 1. Connection failure 2. Outside cause 3. Transmission PCB failure 4. Controller PCB failure
06-18