Failure Diagnosis Of The Gps Section - Kenwood NX-5700 Service Manual

5.2

Failure diagnosis of the GPS section

Over view:
When the GPS function does not operate, use this flowchart to determine the problem.
Major parts for a GPS circuit
GPS antenna (KRA-40 (option))
Coaxial cable (E0E-0003-00)
SAW Filter (L9)
Bluetooth/GPS IC (IC5)
Level conversion IC (IC6,IC7)
TCXO 19.2MHz (X1)
32.768kHz clock (X2)
33BT Regulator (IC3)
18BT Regulator (IC2)
33GPS Regulator (IC4)
MPU/DSP IC (IC706)
Positioning is not carried out normally.
When the power supply is ON,
"GPS Ant Fail" is displayed.
When an abnormal
condition is confirmed.
Verify the connection of KRA-40.
(SMA connector)
When a normal
condition is confirmed.
Verify the connection of the SMA
connecting cable.
CN5 - E0E-0003-00
When a normal
condition is confirmed.
Check the Module (BT/GPS) unit PCB side B.
Check the Module (BT/GPS) unit PCB side A.
Verify the BT/GPS power supply.
(33BT) L4: 3.3V
When a normal
condition is confirmed.
Verify the BT/GPS power supply.
(18BT) L5:1.8V
When a normal
condition is confirmed.
Verify the RTC for the BT/GPS.
X2 (3 pin): square waveform,
32.768kHz, 1.8Vp-p
When a normal
condition is confirmed.
Verify the reference clock for
the BT/GPS.
(BT_CLK) Intersection of C8
and C9: Clipped Sine waveform,
19.2MHz, 0.2 to 1.2 Vp-p
When a normal
condition is confirmed.
Check the Module (BT/GPS) unit PCB side B.
1-98 (No.RA020<Rev.002>)
IC706
UART UART
MPU/DSP
IC
PCM PCM
MAIN UNIT
When a normal
condition is confirmed. Check the Module (BT/GPS)
unit PCB side A.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
[The BT/GPS power supply
When an abnormal
line 33BT circuit faulty]
condition is confirmed.
Visual check of the PCB side A parts.
(Whether not damaged)
L4, C15, C19, C20, C33
Replace any abnormal parts.
[The BT/GPS power supply.
When an abnormal
line 18BT circuit isfaulty]
condition is confirmed.
Visual check of the PCB side A parts.
(Whether not damaged)
C18, C13, C31, L8, C39
Replace any abnormal parts.
When an abnormal
Verify the RTC line circuit for
condition is confirmed.
the BT/GPS.
Visual check of X2, L8, C39
(Whether not damaged)
Replace any abnomal parts.
[The reference clock circuit
When an abnormal
for the BT/GPS is faulty]
condition is confirmed.
Visual check of the R9,Q1 R10,R26
R12, R13, X1, C4, C8, C9
(Whether not damaged)
Replace any abnormal parts.
IC6 IC5
UART
Level
conversion
IC
Matching
BT/GPS
IC
IC7
PCM
Level
conversion
IC
X1 X2
TCXO 32.768kHz
19.2MHz Clock
Connect the KRA-40 correctly.
Connect the cable to
the CN5 correctly.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
L9 GPS antenna unit
SAW
RF
GPS
Filter
Antenna
Bias
coaxial cable
CN5
MODULE (BT/GPS)
UNIT
Check the Module (BT/GPS) unit
PCB side B.
Check the Module (BT/GPS) unit
PCB side B.