Javelin Troubleshooting - Motorola MTM800 User Manual

TROUBLESHOOTING CHARTS: 450-470MHz

JAVELIN Troubleshooting

Failure:
No or low JAVELIN output signal level.
Start
Connect the radio's accessory connector to the
Tetra Com interface.
Connect the radio's antenna connector to the
high power RF output on the IFR.
Run Tetra Com script for TX Power Test
Measure RF levels with the high impedance
RF probe and millivoltmeter.
Measure DC levels with a multimeter.
2.8V DC at
C5875 ?
Yes
5V DC at
TP5811?
Yes
5V DC at
Q5804 p
Yes
5V DC at
TP5841 ?
Yes
0V DC at
R5855 ?
No
Is AC about 750m Vp-p
measured with a scope
at TP5805.....TP5808?
And DC 1.9V?
Yes
RF level at
TP5801 about
200mV ?
Yes
RF level at C5803;
C5813 about
400..600mV ?
Yes
RF level at
TP5811 about
200mV ?
Yes
Before replacing
U5809 check
R5850..R5854
Tetra Com Script for TX Power Test
TEST_ENTER
DELAY 18
Check for "Radio HW is READY"
MODE IDLE
INTR EN
FREQ TX 429.925
L1TIMER ON
TXPOW 6
MODE TXNDC
Use MODE IDLE to terminate transmit mode.
No
No
No
in2 ?
No
> 2V DC at
No
Yes
No
No
No
No
at both sides of L 580
abou t 130...200mV ?
No
TX DC supply fail ur e
Go to DC supply chart
Check Q5301
Yes
Q5802
Check Q5802; Q5804
Pin 4
Before replacing
U5809
check R5850 to R5854
Rep lace U5810
No TX VCO signal
Go to TX fr equency
generation chart
Check components
between TP5801 and
T5801
RF level
Yes
9
Change T5802
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