Keys Do Not Work - Denon DHT-S316 Service Manual

TROUBLE SHOOTING
1. The unit does not power on
Check the cable and connection.
KEY PCB to MAIN PCB
[U4-U18 : 20pin FFC]
OK
Check the voltage.
MAIN PCB [POWER_15V]
OK
Check the voltage.
MAIN PCB [STBY_5V, STB_3V3]
OK
Replace the KEY PCB.

2. Keys do not work

(SoundBar)
Check the cable and connection.
KEY PCB to MAIN PCB
[U4-U18 : 20pin FFC]
OK
Replace the KEY PCB
NG
Check the voltage.
MAIN PCB [U6 : STB_3V3]
NG
Replace the [U6]
(SoundBar)
NG
Replace the FFC.
NG
Replace the POWER PCB.
NG
Replace the MAIN PCB.
NG
Replace the FFC.
OK
Replace the MAIN PCB.
3. BT cannot work
(SoundBar)
Check the power supply voltage.
MAIN PCB [BT VDD, BT_VCC]
OK
Replace the MAIN PCB
4. AUX IN cannot work
Check the cable and connection.
AUX OPT PCB to MAIN PCB
[XP23-XP22 : 8pin FFC]
OK
Replace the AUX OPT PCB
NG
Check the voltage.
MAIN PCB [SYS_3V3, STB_3V3]
NG
Replace the [U11]
37
NG
Replace the [U1].
NG
Replace the FFC.
OK
Replace the MAIN PCB.