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3-26
Maintenance:
Low Band Troubleshooting Charts
Level >
+2 dBm
Check signal at
collector of Q201
No
Yes
Check L204, L211, L212,
L215, C221, C228, C229,
C230,C231, C235,C297,
R204, R234, R238
Troubleshooting Flow Chart for VCO
Check signal at
collector of Q201
No RX LO or No
signal at U205 Pin 32
in RX
No TX LO or No
signal at U205 Pin 32
in TX
Level >
+10 dBm?
Check signal at
drain of Q203
Level >
-3 dBm?
Check signal at
drain of Q202 and
Q204
Level >
+7 dBm?
No
Yes
Replace Q201
Yes
Yes
Done
Check DC voltage
across R203
Problem
fixed?
Replace Q203
Check C215, C216,
L207, L208, L209,
U203
Level >
500 mV?
Check C200, C202, C203,
C222, C223, L201, L203,
TR201, CR202
Replace Q202
and Q204
Yes
Yes
No
No
No
No
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: ......