1-156 (No.RA054<Rev.001>)
5.2
Failure diagnosis of the GPS section (GPS model only)
Overview:
When the GPS function does not operate, use this flowchart to determine the problem.
Fail
Pass
Pass
MPU/DSP
IC
Level
Conversion
IC
Level
Conversion
IC
TCXO
19.2MHz
BT/GPS
IC
RF
Matching
SAW
Filter
GPS
Antenna
Bias
32.768KHz
Clock
GPS Antenna unit
L9
IC5
IC6
Coaxial
cable
X2
X1
IC7
IC404
UART
PCM
UART
TX-RX UNIT
BT/GPS UNIT
CN5
PCM
PCM
UART
Major parts for a GPS circuit
• Coaxial cable: E0E-0003-00
• GPS active antenna: KRA-40 (option)
• SAW Filter (L9)
• Bluetooth/GPS IC (IC5)
• Level conversion IC (IC6, IC7)
• TCXO 19.2MHz (X1)
• 32.768 kHz clock (X2)
• 33BT Regulator (IC3)
• 18BT Regulator (IC2)
• 33GPS Regulator (IC4)
• MPU/DSP IC (IC404)
Positioning is not carried out normally.
Power is not supplied to the KRA-40.
When the power supply is turned ON,
Displayed
“GPS ANT FAIL” is displayed
Not displayed
Fail
Verify the connection of KRA-40.
(SMA connector)
Pass
Verify the connection of the SMA
connecting cable.
CN5 – E0E-0003-00
Pass
Fail
Check the BT/GPS UNIT PCB side A.
Fail
Connect the KRA-40
correctly.
Connect the cable to
the CN5 correctly.
Check the BT/GPS UNIT PCB side B.
CN5 – E0E-0003-00
Verify the connection of the SMA
connecting cable.
Verify the connection of KRA-40.
(SMA connector)
Summary of Contents for NX-3720
Page 188: ...MEMO No RA054 Rev 001 2 20 ...