Kenwood NX-210(G) Service Manual page 35

Failure Diagnosis of the GPS section
■ Overview
When the GPS function does not operate, use this fl ow chart to determine the problem.
■ Major parts for a GPS circuit (TX-RX unit and Sub (GPS) unit)
• GPS IC (IC1/ SUB (GPS))
• LNA IC (IC11/ TX-RX)
• BPF (L17/ TX-RX)
• 33C AVR (IC207/ TX-RX)
• 5A AVR (IC205/ TX-RX)
• 3.1V AVR (IC4/ SUB (GPS))
Positioning is not carried out normally.
Are you using the supplied GPS
antenna?
When a normal
condition is confirmed.
Verify the connection of the GPS coaxial
cable.
When a normal
condition is confirmed.
Verify the GPS power supply.
IC1 (23 pin): 3.3V (SUB (GPS))
When a normal
condition is confirmed.
Verify the LNA power supply.
IC207 (4 pin): 3.3V
When a normal
condition is confirmed.
Verify the GPS control signal (OPT5).
High (3.3V)
When a normal
condition is confirmed.
Verify the RF input circuit for the GPS.
Antenna receptacle, HPF, BPF, LNA
When a normal
condition is confirmed.
Verify the GPS data (RXD).
R9: Square waveform
High (3.3V)
When a normal
condition is confirmed.
TROUBLE SHOOTING
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
When an abnormal
condition is confirmed.
Verify the 5A.
(IC205/ TX-RX)
When a normal
condition is confirmed.
Verify the following
power supply parts:
IC4, L1 (SUB (GPS))
Replace any abnormal parts.
When an abnormal [The power supply line circuit for
condition is confirmed.
LNA is faulty]
Verify the 33C.
Replace any abnormal parts.
When an abnormal
condition is confirmed.
Verify the state of the OPT5 line.
When a normal
condition is confirmed.
[The ASIC IC is abnormal]
Verify the state of the ASIC
(IC309 (TX-RX)).
When an abnormal
condition is confirmed.
HPF part C25, L19, C24, L18, C23, L20,R18, D12, D13
BPF part L17, C22
LNA part C21, L16, IC11, C18, R14, R15, R17
(All parts/ TX-RX)
When an abnormal
condition is confirmed.
Verify the state of the RXD1 line.
When a normal
condition is confirmed.
[The ASIC IC is abnormal]
Verify the state of the ASIC
(IC309 (TX-RX)).
NX-210(G)
Connect the supplied GPS antenna
correctly.
Connect the GPS coaxial cable
correctly.
When an abnormal
condition is confirmed.
Verify the 5A.
Replace any abnormal parts.
When an abnormal
[The OPT5 control line circuit
condition is confirmed.
is faulty]
Replace any abnormal parts.
[The GPS RF input circuit is faulty]
Replace the GPS RF input circuit parts.
(only the parts which can be replaced.)
When an abnormal
condition is confirmed.
[The RXD1 line circuit is faulty]
Replace any abnormal parts.
35