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3-20
Maintenance:
VHF Troubleshooting Charts
START
No LO?
Tx Carrier?
VCO OK
Check
R3829
TRB = 3.2V?
Pin 10
>1V?
L3831,
L3832,
L3833 O/
C?
Change
L3831, L3832
Change
U3801
AUX 3
High?
Check U3701
Pin 2 for 3.2V
Pin 19
=0V
AUX 3
Low?
Change
U3801
V ctrl 0V
or 13V?
L3821,
L3822,
L3823 Open
Circuit?
Change
U3801
Change
L3821,
L3822,
L3823,L243
Change
U3701
Check for faulty parts or dry
joints of L3812 C3806,
R3806, R3802 & L3801
A
A
No
No
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
Yes
No
No
Yes
Yes
No
No
Check R3811,
L3811 for dry joint
or faulty
No
Troubleshooting Flow Chart for VCO
Yes
Содержание PR860
Страница 1: ...PR860 Two Way Portable Radio Detailed Service Manual ...
Страница 2: ......
Страница 5: ...iv Notes ...
Страница 9: ...viii Table of Contents Notes ...
Страница 13: ...Notes xii List of Figures ...
Страница 17: ...1 4 Introduction Radio Model Information Notes ...
Страница 51: ...2 34 Theory of Operation Voltage Control Oscillators VCO Notes ...
Страница 81: ...4 4 Schematic Diagrams Overlays and Parts Lists Flex Layout Notes ...
Страница 193: ...4 116 Schematic Diagrams Overlays and Parts Lists Low Band Section Notes ...
Страница 196: ......