Kenwood NX-5800 Service Manual page 115

When a normal
condition is confirmed.
Verify the BT/GPS control
signal (RXD2).
CN1 (7 pin): Square waveform
UART data of 3.3V logic.
Baud rate:
Default: 115.2kbps
After: 3.967Mbps.
When a normal
condition is confirmed.
[The BT/GPS IC is abnormal
Replace the PCB.
Check the PCB side B (a).
When a normal
condition is confirmed.
[The BT/GPS power supply line 33BT circuit is faulty]
Replace the
C5, C46, C44, C49.
Check the PCB side B (b).
When a normal
condition is confirmed.
[The BT/GPS power supply line 18BT circuit is faulty]
Replace the
C2, C47, L5, L13, C45, C48.
Check the Main unit PCB.
When a normal
condition is confirmed.
Verify the BT/GPS control
signal (TXD2).
CN735 (15 pin): Square
waveform UART data of 3.3V
logic.
Baud rate
Default: 115.2kbps
After: 3.967Mbps.
When a normal
condition is confirmed.
Verify the BT/GPS control
signal(RXD2).
CN735 (14 pin): Square waveform
UART tada of 3.3V logic.
Baud rate:
Default: 115.2kbps
After: 3.967Mbps.
When a normal
condition is confirmed.
[The MPU/DSP IC is 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
Verify the BT/GPS control
condition is confirmed.
signal (18BT_HCI_TX.).
IC6 (18 pin):
Square waveform UART data
of 1.8V logic.
[The RXD2 (18BT_HCI_TX)
line circuit is faulty]
Visual check of the CP1, IC6, R22
Replace any abnormal parts.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
Verify the BT/GPS control
When an abnormal
signal (G_TXD2).
condition is confirmed.
CP705 (3 pin):
Square waveform UART data
of 3.3V logic.
[The RXD2 (18BT _HCI_TX)
line circuit is faulty]
Replace the CP705.
When an abnormal Verify the BT/GPS control
condition is confirmed.
signal (18BT_HCI_TX).
CP705, (4 pin):
Square waveform UART data
of 1.8V logic.
[The RXD2 (18BT _HCI_TX)
line circuit is faulty]
Replace the CP705.
When an abnormal
condition is confirmed.
When an normal
condition is confirmed.
[The BT/GPS IC is abnormal]
Replace the PCB.
[The BT/GPS IC is abnormal]
Replace the PCB.
When an abnormal
condition is confirmed.
When an normal
condition is confirmed.
When an abnormal
condition is confirmed.
When an normal
condition is confirmed.
Active, Low Reset
Check the Main unit PCB (c).
[The MPU/DSP IC is abnormal
Replace the PCB.
[The MPU/DSP IC is abnormal]
Replace the PCB.
(No.RA017<Rev.003>)1-115