Kenwood NX-5300 Service Manual page 108

When a normal
condition is confirmed.
Verify the reference clock for the BT/GPS.
(BT_CLK) Intersection of
C850 and R861: Sine waveform,
19.2MHz, 0.2 to 1.2 Vp-p
When a normal
condition is confirmed.
Verify the LNA power supply
VDD_TCXO (G1 pin) of IC850
(Intersection of C855 and R862): 1.8V
When a normal
condition is confirmed.
Verify the BT/GPS control
signal (18BT_HCI_RX).
IC852 (8 pin):
Square waveform UART data
of 1.8V logic.
Baud rate:
Default: 115.2kbps
After: 3.967Mbps.
When a normal
condition is confirmed.
Verify the BT/GPS control
signal (RXD2).
CP851 (1 pin): Square waveform
UART data of 3.3V logic.
Baud rate:
Default: 115.2kbps
After: 3.967Mbps.
When a normal
condition is confirmed.
Check the PCB side B.
Check the PCB side B.
When a normal
condition is confirmed.
Verify the LNA ENABLE.
IC851 (6 pin): 1.8V
When a normal
condition is confirmed.
1-108 (No.RA015<Rev.002>)
[The reference clock circuit
When an abnormal
for the BT/GPS is faulty].
condition is confirmed.
Verify the PCB side A parts
C850, R861, R862.
Replace any abnormal parts.
When an abnormal
[The power supply line circuit
condition is confirmed.
for LNA is faulty]
Verify the C855, R862 and R851.
Replace any abnormal parts.
Verify the BT/GPS control
When an abnormal
signal (TXD2).
condition is confirmed.
CP851 (2 pin):
Square waveform UART data
of 3.3V logic.
[The 18BT_HCI_RX (TXD2)
line circuit is faulty]
Verify the CP851, IC852, R858
Replace any abnormal parts.
Verify the BT/GPS control
When an abnormal
signal (18BT_HCI_TX).
condition is confirmed.
IC852 (8 pin):
Square waveform UART data
of 1.8V logic.
[The RXD2 (18BT_HCI_TX)
line circuit is faulty]
Verify the CP851, IC852, R858
Replace any abnormal parts.
When an abnormal
[The LNA ENABLE line is faulty]
condition is confirmed.
Verify the R860.
Replace any abnormal parts
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When a normal
condition is confirmed.
When an abnormal
condition is confirmed.
When a normal
condition is confirmed.
When an abnormal
condition is confirmed.
Check the PCB side B (c).
[VDD_TCXO (G1 pin) of
IC850 is faulty]
Replace the PCB
[MPU/DSP (IC702) is faulty]
Replace the PCB.
[BT/GPS IC (IC850) is faulty]
Replace the PCB.
[GPS_EXT_LNA_EN
(H6 pin) of IC850 is
faulty]
Replace the PCB.