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Section 4: 3-4
Troubleshooting Flow Chart for 25 W Transmitter
2.1
Troubleshooting Flow Chart for 25 W Transmitter (Sheet 2 of 3)
Check PA Stages
No power or low power when keyed
Measure DC Voltage at Pin 2 & 3 of U3401
>6
YES
DC Voltage
at U3501
Pin 23 =0?
2-6
DC Voltage
at U3402-1
Pin 1?
YES
Pin 2 Volt-
age 0.62 *
Voltage at
Pin 1?
If U3201 Pin 2 is high,
replace PCIC
NO
Replace U3401
YES
NO
DC
Voltage at
U3402-1 Pin
3 = 8.8V?
Check S3440,
R3442 and R3443
YES
Pin 3 Volt-
age 0.51 *
Voltage at
Pin 1?
NO
Replace U3401
<2V
DC Voltage
at U3402-2
Pin 7?
>6V
Check Components
between U3402-2 Pin 7
and Q3421. Check
Resistive Network at
Pins 5 & 6 before
replacing Q3421
YES
DC Voltage
at U3402-2
Pin 5 <8.8V?
Check Components
between U3402-2 Pin 7
and Q3421. Check Resis-
tive Network at Pins 5 & 6
before replacing Q3421
NO
Check Q3422
NO
Check Final PA Stage
2-6V
<2V
Check Resistive Net-
work at Pins 2 & 3 of
U3402-1 before replac-
ing U3401
Check Q3442 and
Resistive Network at
U3402-1 Pin 3
before replacing
U3401
Summary of Contents for PRO Series
Page 1: ...CDM Series and PRO Series Two Way Mobile Radios Detailed Service Manual 6881091C63 F ...
Page 4: ...Notes ...
Page 6: ...Notes ...
Page 8: ...Section 1 ii 6881091C63 F Notes ...
Page 12: ...Section 1 1 4 Radio Model Information 6881091C63 F Notes ...
Page 22: ...Section 1 2 10 Notes For All Schematics and Circuit Boards 6881091C63 F Notes ...
Page 46: ...Section 2 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 78: ...Section 3 1 20 Controller Board Audio and Signaling Circuits Section 6881091C63 F Notes ...
Page 80: ...Section 3 2 2 Troubleshooting Flow Chart for Controller 6881091C63 F Notes ...
Page 84: ...Section 3 3 4 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 146: ...Section 3 3 66 Controller T6 T7 Schematics and Parts Lists 8471235L06 Notes 6881091C63 F ...
Page 152: ...Section 4 1 4 Technical Specifications 6881091C63 F Notes ...
Page 168: ...Section 4 3 8 Troubleshooting Flow Chart for VCO 6881091C63 F Notes ...
Page 172: ...Section 4 4 4 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 232: ...Section 5 1 4 Technical Specifications 6881091C63 F Notes ...
Page 242: ...Section 5 2 10 UHF Band 1 403 470 MHz 1 25 W Frequency Synthesis 6881091C63 F Notes ...
Page 296: ...Section 6 1 4 Technical Specifications 6881091C63 F Notes ...
Page 306: ...Section 6 2 10 UHF Band 2 450 512 527 MHz 1 25 W Frequency Synthesis 6881091C63 F Notes ...
Page 316: ...Section 6 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 352: ...Section 7 3 6 Troubleshooting Flow Chart for VCO 6881091C63 F Notes ...
Page 356: ...Section 7 4 4 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 458: ...Section 8 1 4 Technical Specifications Section 6881091C63 F Notes ...
Page 474: ...Section 8 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 496: ...Section 9 1 4 Technical Specifications Section 6881091C63 F Notes ...
Page 512: ...Section 9 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 530: ...Section 10 1 4 Technical Specifications Section 6881091C63 F Notes ...
Page 546: ...Section 10 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 564: ...Section 11 1 4 Technical Specifications 6881091C63 F Notes ...
Page 580: ...Section 11 3 8 Troubleshooting Flow Chart for VCO 6881091C63 F Notes ...
Page 582: ...Section 11 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 608: ...Section 12 1 4 Technical Specifications 6881091C63 F Notes ...
Page 624: ...Section 12 3 8 Troubleshooting Flow Chart for PassPort 6881091C63 F Notes ...
Page 626: ...Section 12 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...
Page 654: ...Section 13 1 4 Technical Specifications 6881091C63 F Notes ...
Page 672: ...Section 13 4 2 Allocation of Schematics and Circuit Boards 6881091C63 F Notes ...