Motorola ASTRO Digital Saber Service Manual page 107

No/Low Power
NO
TX Current
> 500 mA?
YES
YES RF at RF
Check antenna
Connector,J2
switch
Pin 2?
NO
Check Components RF at
YES
Between C147 Cathode of
and L128
CR108?
NO
Check Antenna
RF Present
YES
Switch Biasing
at Anode
Circuits, L122,
of CR108?
L105, U101
NO
Check Components
Between U105
and U201. If No
YES RF Present
Replace U104
at Pin 5 of Fault Found,
Go To FGU
U104?
Troubleshooting
Chart C.31
NO
Replace U105
NO
Replace U101 About 3.5V
About 1.5V?
YES
NO
Go to DC Switch
Is T5 On
Routine Chart C.36
at C153?
YES
B+ at Check B+, E1 & E101
U105, Pin 5 NO (VHF), E1, E2, E3 &
(VHF) E101, E104 (UHF) and
5,6 (UHF)?
Power Supply
YES
7V at
7.5V at 7.5V at
NO
Collector
U105 U105
of Q101?
Pin 2,4? Pin 2.4?
YES NO
Voltage Voltage 5V at
NO
at U105 at U105 U101,
Pin 3? Pin 3? Pin 16?
YES
YES
NO RF Voltage RF Voltage 7.5V at
at U105, at U105, Emitter of
Pin 1? Pin 1? Q101?
YES
YES
Replace U105
Voltage at
Q101 Base
is B+ Less
0.7V?
U101
U101,
Pin 3
YES
Pin 2,7
NO
Pin 6 About 2.5V
to 4V?
Voltage at U101
Pin 14 > 1V?
NO
Check Detector
NO
Circuit, CR102, (VHF),
CR101 (UHF), CR103,
R110, R111, U102
Replace U102
Chart 38 . VHF/UHF Transmitter RF
YES
Check L102, L103 (UHF)
L102, L130 (VHF)
Go to FGU No Lo
NO
Injection/TX Not
Lock Routine
Chart #4A
NO
Check Power
Supply
YES
Replace Q101
YES
Replace U101
MAEPF-24393-O
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