Kenwood NX-3220 K Service Manual page 154

Check the PCB side B (a).
[The BT/GPS power supply line 32BT circuit is
faulty]
Verify the PCB side B parts.
L351, C388, C363, C364, C372
Replace any abnormal parts.
Check the PCB side B (b).
[The BT/GPS power supply line 18BT circuit is
faulty]
Verify the PCB side A parts.
L352, R361, R360, C358, C370, L358, C375,
X351. Replace any abnormal parts.
Check the PCB side B (c).
[The reference clock circuit for the BT/GPS is
faulty]
Verify the PCB side B parts
X401(OUTPUT pin): Clipped sine wave,
X401(VCC pin): 3.2V,
R401, R403, C402, C403, R404, C404, R405,
R406, R410,
Q401(B, E): Clipped sine wave, Q401(C): 3.2V,
R407, C405, C407, R408, C406, L402, C408,
R412, R413, R414, C303, IC303
Replace any abnormal parts.
If any unexchangeable parts are abnormal,
replace the PCB.
Descriptions of signal names
(1) 32BT: BT/GPS IC 3.2V power supply
(2) 18BT: BT/GPS IC 1.8V power supply
(3) TXD2: BT/GPS serial data line connected to UART TX of MPU/DSP IC (MPU/DSP to BT/GPS IC)
(4) RXD2: BT/GPS serial data line connected to UART RX of MPU/DSP IC (MPU/DSP to BT/GPS IC)
(5) 18BT_HCI_RX: BT/GPS serial data line connected to UART RX of BT/GPS IC (MPU to BT/GPS IC)
(6) 18BT_HCI_TX: BT/GPS serial data line connected to UART TX of GPS IC (BT/GPS IC to MPU)
(7) /BT_SHUTDOWN: BT/GPS active control of MPU/DSP IC (MPU/DSP to BT/GPS IC) High → Active, Low → Reset
1-154 (No.RA053<Rev.001>)
Pass
Pass
Pass
[The BT/GPS IC is
Fail
abnormal]
Replace the PCB.
[The BT/GPS IC is
Fail
abnormal]
Replace the PCB.
[The BT/GPS IC is
Fail
abnormal]
Replace the PCB.