Daikin FTX50K(M/2)V1B - Indoor Unit PCB Abnormality

SiBE041525F Troubleshooting
Service Diagnosis 50
4.2 Indoor Unit PCB Abnormality
Error Code A1
Method of Error
Detection
The system checks if the circuit works properly within the microcomputer of the indoor unit.
Error Decision
Conditions
The system cannot set the internal settings.
Supposed
Causes
 Wrong models interconnected
 Defective indoor unit PCB
 Disconnection of connector
 Reduction of power supply voltage
Troubleshooting
Note: Check the following connector.
Check the connection of
connectors (See Note.).
Correct the connection.
OK?
Check the power supply
voltage.
Start operation.
Voltage as rated?
Error repeats?
Check the power supply
voltage.
Start operation.
Voltage as rated?
Error repeats?
Error repeats?
Combination of
the indoor and outdoor
unit matched?
YES
NO
NO
YES
NO
NO
YES
(R20486)
Caution
∗ To secure the connection,
once disconnect the connector
and then reconnect it.
YES
NO
YES
NO
YES
NO
YES
Match the compatible
models.
Correct the power
supply.
Replace the indoor unit
PCB (control PCB).
Completed.
Completed.
Correct the power
supply.
Replace the indoor unit
PCB (control PCB).
Completed.
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Model Type Connector
20/25/35 class Terminal board ~ Control PCB (H1, H2, H3)
50/60/71 class Terminal board ~ Filter PCB (S100)