Kenwood NX-5400 Service Manual page 71

Check the PCB side B (a).
When a normal
condition is confirmed.
[The BT/GPS power supply line 33BT circuit is
faulty]
Verify the PCB side B parts.
IC39, IC38, C55, L850
Replace any abnormal parts.
Check the PCB side B (b).
When a normal
condition is confirmed.
[The BT/GPS power supply line 18BT circuit is
faulty]
Verify the PCB side A parts.
IC37, L38, C52, C53, L851, L854, C875
Replace any abnormal parts.
Check the PCB side B (c).
When a normal
condition is confirmed.
[The reference clock circuit for the BT/GPS is faulty]
Verify the PCB side B parts.
X700 (OUTPUT pin): Clipped sine wave,
X700 (VCC pin): 3.3V,
R700, R702, C701, C702, R704, C703, R705,
R706, R780,
Q700 (B, E): Clipped sine wave, Q700(C): 3.3V,
R707, C704, C706, R708, C705, L701, C707,
R772, C708
Replace any abnormal parts.
If any unexchangeable parts are abnormal,
replace the PCB.
Descriptions of signal names
1) 33BT: BT/GPS IC 3.3V 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
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
[The BT/GPS IC is abnormal]
Replace the PCB.
[The BT/GPS IC is abnormal]
Replace the PCB.
[The BT/GPS IC is abnormal]
Replace the PCB.
Active, Low
(No.RA016<Rev.001>)1-71
Reset