3-4
Troubleshooting Flow Chart for 45W Transmitter
2.1
Troubleshooting Flow Chart for 45W Transmitter (Sheet 2 of 2)
Pin 2
Voltage 0.62
* Voltage at
Pin 1?
NO
YES
Check PA Stages
No or too low Power when keyed
NO
YES
Replace U3401
Pin 3
Voltage 0.51
* Voltage at
Pin 1?
2-4V
Supply
0V
Bias 1 DC
Voltage at
TP3406?
NO
YES PCIC U3501
Pin 24 2-4V
DC?
Check Bias Tuning be-
fore replacing
PCIC U3501
Check Voltage at Pin 2 & 3 of U3401
Replace U3401
Replace Q3421
NO
0V
1-4V
Bias 2 DC
Voltage at
TP3407?
YES
RF Voltage
at TP3401
>100mV?
YES
RF Voltage
U3401 Pin 6
>3V?
Replace
Q3421
Supply
Replace Q3431
Check FGU (U3301)
NO
Check Components
between TP3401 &
C3417
NO
YES
ASFIC
U0221 Pin 6
1-4V DC?
Check Bias Tuning be-
fore replacing
ASFIC U0221
Check Components
between ASFIC and
Q3431 before re-
placing Q3431
YES
RF Voltage
Q3421 Gate
>1V?
NO
Check Components
between C3417 &
Q3421
YES
RF Voltage
Q3431 Gate
>4V?
NO
Check Components
between Q3421 &
Q3431
YES
RF Voltage
Q3441 Base
>5V?
Check Components
between Q3431 &
Q3441
NO
Check Components
between Q3441 & An-
tenna Connector
Voltage
Voltage
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 ...