Panasonic WH-ADF0309J3E5CM Service Manual page 264

25.2.18 Indoor-Control Panel Communication Abnormality (- / - / H76)
Malfunction Decision Conditions:
During standby and operation of cooling and heating, indoor-control panel error occur.
Malfunction Caused:
1. Faulty connector connection.
2. Faulty control panel.
3. Faulty indoor unit PCB (main).
Troubleshooting:
Check the CN4 connector connection:
- Turn OFF the power
- Check the connector connection
Is the CN4 connector
connection normal?
Yes
Check the control panel
cable connection.
Is the control panel cable
connection normal?
Yes
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Caution
No
- Connector poor contact.
- Correct the connection.
No
- Defect in cable connection.
- Replace control panel cable.
Check the Vdc from the indoor unit PCB (main):
- Disconnect remote control from the indoor unit PCB
terminal CN4
- Turn ON the power.
- Measure the Vdc as shown in Figure 1.
- Is the Vdc measurement 16Vdc?
No
- Defect in indoor unit PCB
(main).
- Replace the indoor unit PCB
(main).
264
- Defect in remote control
Yes
(control panel).
- Replace the remote
control (control panel).
16Vdc
Figure 1