Kenwood NX-5300 Service Manual page 110

5.3 Failure diagnosis of the Bluetooth section
Overview:
When the Bluetooth function does not operate, use this flowchart to determine the problem.
Major parts for a Bluetooth circuit
Bluetooth antenna (Connect on CN909)
LC filter (L855)
Bluetooth/GPS (IC850)
Level conversion IC (IC852, IC853)
TCXO 19.2MHz (X700)
Clock Buffer (IC700)
32.768kHz clock (X850)
33BT Regulator (IC38)
18BT Regulator (IC37)
MPU/DSP IC (IC702)
I can not pair with the Bluetooth (BT) headset.
Make sure the BT headset have enough power?
Turn on your BT headset?
Put your BT headset into pairing mode?
Yes
Verify the contact of the BT internal
antenna with the PCB.
When a normal
condition is confirmed.
Check the PCB side A.
Check the PCB side A.
Verify the ANT Matching Parts.
Verify check to L863, C893, L855,
C873.
When a normal
condition is confirmed.
Verify the BT/GPS power supply.
(33BT) L862: 3.3V
When a normal
condition is confirmed.
Verify the BT/GPS power supply.
(18BT) L861: 1.8V
When a normal
condition is confirmed.
Verify the BT/GPS control
signal (/BT_SHUTDOWN).
R853: 1.8V
When a normal
condition is confirmed.
1-110 (No.RA015<Rev.002>)
IC702
MPU/DSP
X700
TCXO
19.2MHz
No
When an abnormal
condition is confirmed.
[The BT/GPS power supply
When an abnormal
line 33BT circuit is faulty]
condition is confirmed.
Verify the PCB side A parts.
C856, C860, C861, C870
L862, C885, C890
Replace any abnormal parts.
When an abnormal [The BT/GPS power supply
condition is confirmed. line 18BT circuit is faulty]
Verify the PCB side A parts.
C859, C852, C868, L861,
C891, C844
Replace any abnormal parts.
When an abnormal
[MPU/DSP (IC702) is faulty]
condition is confirmed.
Replace the PCB.
IC852
UART UART
Level
conversion
IC
IC
IC853
PCM PCM
Level
conversion
IC
IC700
Clock
Buffer
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
IC850
Shee t metal
L855
Bluetooth
LC
Antenn a
Filter
BT/GPS
IC
X850
32.768 kHz
Clock
Charge the BT headset. Turn on your BT headset and bring it
within one to two meters.
Try again pair with BT headset.
To reassembly correctly the BT antenna.
If an antenna is defective, replace the BT internal antenna.
Replace any abnormal parts.
Check the PCB side B (a).
Check the PCB side B (b).