Fujitsu AO G24LBCB Series Service Instruction page 41

Trouble shooting 12
INDOOR UNIT Error Method:
Indoor unit Communication circuit
(wired remote controller) error
Detective Actuators:
Indoor unit Controller PCB circuit
Forecast of Cause :
1.Communication PCB defective
2. Indoor unit controller PCB defective
Check Point 1 : Check the connection of terminal
After turning off the power supply, check & correct the followings
Indoor unit - Check the connection the communication PCB and the controller PCB
OK
Check Point 2 : Replace the communication PCB
If the Check point 1 is ok, replace the communication PCB
OK
Check Point 3 : Replace the controller PCB
If condition is doesn't change, replace the controller PCB
Indicate or Display:
Error code : 3A
Detective details:
Detect the communication error of microcomputer and communication PCB.
02-13
Outdoor unit : No indication