Kenwood NX-200 Service Manual page 36

NX-200(G)
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 (IC881/ TX-RX)
• BPF (L883/ TX-RX)
• 33C AVR (IC903/ TX-RX)
• 5A AVR (IC708/ CONT)
• 3.1V AVR (IC4/ SUB (GPS))
Positioning is not carried out normally.
Are you using the supplied GPS
antenna?
Verify the connection of the GPS coaxial
cable.
Verify the GPS power supply.
IC1 (23 pin): 3.3V (SUB (GPS))
Verify the LNA power supply.
IC881 (4 pin): 3.3V
Verify the GPS control signal (OPT5).
High (3.3V)
Verify the RF input circuit for the GPS.
Antenna receptacle, HPF, BPF, LNA
Verify the GPS data (RXD).
R9: Square waveform
High (3.3V)
36
TROUBLE SHOOTING
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.
When a normal
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.
HPF part C508, L505, C507, L504, C506, D501, D502
BPF part L503, C503
LNA part C504, L502, IC501, C501, R505, R503, R502
When a normal
(All parts/ TX-RX)
condition is confirmed.
When an abnormal
condition is confirmed.
When a normal
condition is confirmed.
When an abnormal
condition is confirmed.
Verify the 5A.
(IC708/ CONT)
When a normal
condition is confirmed.
Verify the following
power supply parts:
IC4, L1 (SUB (GPS))
Replace any abnormal parts.
[The power supply line circuit for
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
(IC108 (CONT)).
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
(IC108 (CONT)).
Connect the supplied GPS antenna
correctly.
Connect the GPS coaxial cable
correctly.
Verify the 5A.
Replace any abnormal parts.
[The OPT5 control line circuit
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.)
[The RXD1 line circuit is faulty]
Replace any abnormal parts.