3-2
Troubleshooting Flow Chart for Receiver
1.1
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
IF Signal at
C3101?
No
RF
Signal at
T4051?
RF
Signal at
C4015?
No
No
RF
Signal at
C4025?
No or
Check harmonic filter
L4491-L4493, C4492, J4401
and ant. switch
D4471, D4472, L4472.
Check filter between
C4025 & C4009.
Check tuning voltage
at R4060.
Inject RF into J4401
Is
tuning voltage
OK?
No
Yes
Check RF amp (Q4003)
Stage.
Check filter between
C4015 & T4051.
Yes
Check T4051, T4052,
D4051, R4052, L4008.
Yes
1st LO level
OK?
Locked?
Yes
Check FGU
Yes
Trace IF signal
from C3101 to
Q3101. Check for
bad XTAL filter.
No
Yes
IF
signal at Q3102
collector?
Before replacing
U3101, check
U3101 voltages.
Yes
Check for
5VDC
Is 9V3
present?
Check Supply Voltage
circuitry. Check Q0681,
U4211 and U0641.
No
No
No
Check U4501.
Check varactor filter.
No
Yes
Yes
Yes
A
A
B
weak RF
RF
Signal at
C4009?
Summary of Contents for GM338
Page 1: ...GM328 GM338 GM398 Mobile Radios Detailed Service Manual 6804112J18 E December 2003 ...
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Page 6: ...THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 7: ...GM328 GM338 GM398 Mobile Radios Service Maintainability Issue December 2003 ...
Page 14: ...vi THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 16: ...viii THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 20: ...1 4 Radio Model Information THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 32: ...2 12 Notes For All Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 35: ...GM328 GM338 GM398 Mobile Radios Controlhead Service Information Issue December 2003 ...
Page 42: ...1 4 GM398 Model GCN6115_ THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 56: ...2 14 Controlhead Model for GM398 THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 70: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 88: ...4 20 Controlhead GM398 PCB 8486178B03 Schematics THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 89: ...GM328 GM338 GM398 Mobile Radios Controller Service Information Issue December 2003 ...
Page 114: ...2 2 Controller Troubleshooting Chart THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 140: ...3 26 Controller T7 T9 Schematic Diagrams THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 141: ...GM328 GM338 GM398 Mobile Radios VHF 136 174MHz Service Information Issue December 2003 ...
Page 148: ...1 4 Technical Specifications THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 158: ...2 10 VHF 136 174 MHz Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 166: ...3 8 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 168: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 186: ...4 20 VHF 1 25W PCBs Schematics Parts Lists THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 187: ...GM328 GM338 GM398 Mobile Radios UHF 403 470MHz Service Information Issue December 2003 ...
Page 204: ...2 10 UHF 403 470 MHz Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 212: ...3 8 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 214: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 235: ...GM328 GM338 GM398 Mobile Radios UHF Band 2 450 527MHz Service Information Issue December 2003 ...
Page 252: ...2 10 UHF 450 527 MHz Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 260: ...3 8 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 262: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 274: ...4 14 UHF Band 2 1 25W PCBs Schematics Parts List THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 275: ...GM338 GM398 Mobile Radios Low Band Service Information Issue December 2003 ...
Page 280: ...iv THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 284: ...1 4 Technical Specifications THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 300: ...3 6 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 378: ...4 78 Low Band PCBs Schematics Parts Lists THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 379: ...GM338 Mobile Radios VHF 45W Bipolar 136 174MHz Service Information Issue December 2003 ...
Page 400: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 411: ...GM338 Mobile Radios UHF1 40W Bipolar 403 470MHz Service Information Issue December 2003 ...
Page 426: ...2 10 Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 432: ...3 6 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 434: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 446: ...4 14 UHF 25 40W PCB Schematics Parts List THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 447: ...GM338 Mobile Radios UHF2 40W Bipolar 450 520MHz Service Information Issue December 2003 ...
Page 462: ...2 10 Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 468: ...3 6 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 470: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 482: ...4 14 UHF Band 2 25 40W PCB Schematics Parts List THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 483: ...GM338 Mobile Radio UHF B1 HIGH POWER LDMOS 403 470MHz Service Information Issue December 2003 ...
Page 498: ...2 10 UHF 403 470 MHz Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 506: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 518: ...4 14 UHF 25 40W PCB Schematics Parts List THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 534: ...2 10 UHF 450 520 MHz Frequency Synthesis THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 540: ...3 6 Troubleshooting Flow Chart for VCO THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 542: ...4 2 Allocation of Schematics and Circuit Boards THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 554: ...4 14 UHF Band 2 25 40W PCB Schematics Parts List THIS PAGE INTENTIONALLY LEFT BLANK ...