(No.RA015<Rev.001>)1-69
5.3
Failure diagnosis of the Bluetooth section
Overview:
When the Bluetooth function does not operate, use this flowchart to determine the problem.
I can not pair with the Bluetooth (BT) headset.
No
Yes
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)
Replace any abnormal parts.
Verify the BT/GPS power supply.
(33BT) L862: 3.3V
Check the PCB side A.
Check the PCB side A.
Verify the ANT Matching Parts.
Verify check to L863, C893, L855,
C873.
[The BT/GPS power supply
line 33BT circuit is faulty]
Verify the PCB side A parts.
C856, C860, C861, C870
L862, C885, C890
Replace any abnormal parts.
Replace any abnormal parts.
Check the PCB side B (a).
Verify the BT/GPS power supply.
(18BT) L861: 1.8V
[The BT/GPS power supply
line 18BT circuit is faulty]
Verify the PCB side A parts.
C859, C852, C868, L861,
C891, C844
Check the PCB side B (b).
Verify the BT/GPS control
signal (/BT_SHUTDOWN).
R853: 1.8V
[MPU/DSP (IC702) is faulty]
Replace the PCB.
IC702
IC852
IC850
UART
UART
L855
IC853
Shee t metal
PCM
PCM
X700
IC700
X850
MPU/DSP
IC
BT/GPS
IC
TCXO
19.2MHz
32.768 kHz
Clock
LC
Filter
Bluetooth
Antenn a
Clock
Buffer
Level
conversion
IC
Level
conversion
IC
Make sure the BT headset have enough power?
Turn on your BT headset?
Put your BT headset into pairing mode?
Charge the BT headset. Turn on your BT headset and bring it
within one to two meters.
Try again pair with BT headset.
Verify the contact of the BT internal
antenna with the PCB.
To reassembly correctly the BT antenna.
If an antenna is defective, replace the BT internal antenna.
When a normal
condition is confirmed.
When a normal
condition is confirmed.
When a normal
condition is confirmed.
When a normal
condition is confirmed.
When a normal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.