Troubleshooting Table for Board and IC Signals
3-15
U480
Dual Opamp
1
Unit 1 output
2.48
2
Unit 1 (-) input
2.48
3
Unit 1 (+) input
2.46
4
Ground
GND
5
Unit 2 (+) input
0.28
6
Unit 2 (-) input
0.29
7
Unit 2 output
0
8
Vcc
4.96
U490
Audio Power Amp
1
Enable/shutdown
0.12
(Unsquelched)
2
Bias reference
3.26
(Unsquelched)
3
(+) input
3.26
(Unsquelched)
4
(-) input
3.27
(Unsquelched)
5
(-) output
3.25
(Unsquelched)
6
Vcc
7.48
(Unsquelched)
7
Ground
GND
8
(+) output
3.29
(Unsquelched)
U510
Dual Opamp
1
Unit 1 output
1.75
2
Unit 1 (-) input
1.56
3
Unit 1 (+) input
1.55
4
Ground
GND
5
Unit 2 (+) input
1.55
6
Unit 2 (-) input
1.56
7
Unit 2 output
1.38
8
Vcc
4.96
1. All voltages are measured with a high-impedance digital voltmeter and expressed in volts DC relative to ground (0V).
2. Voltages are measured with a DC input voltage of 7.50 + .02 volts DC applied to the battery connector (J301).
3. All voltages are measured in the squelched receive mode, unless otherwise indicated.
IC Designator
Pin
Pin Function
DC Voltage
Comments (Condition)
Summary of Contents for CP 140
Page 1: ...Commercial Series CP140 CP160 CP180 Portable Radios Detailed Service Manual 6866550D20 O ...
Page 2: ...ii ...
Page 4: ...iv ...
Page 12: ...viii ...
Page 28: ...iv ...
Page 40: ...1 12 THEORY OF OPERATION ...
Page 48: ...2 8 TROUBLESHOOTING TABLES ...
Page 50: ...3 2 CONTROLLER KEYPAD SCHEMATICS ...
Page 58: ...3 10 Keypad Board Parts List 8466565A01 O ...
Page 62: ...iv ...
Page 66: ...1 4 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 90: ...3 16 TROUBLESHOOTING TABLES ...
Page 92: ...4 2 VHF PCB SCHEMATICS PARTS LISTS ...
Page 108: ...iv ...
Page 112: ...1 4 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 136: ...3 16 TROUBLESHOOTING TABLES ...
Page 138: ...4 2 UHF1 PCB SCHEMATICS PARTS LISTS ...
Page 154: ...iv ...
Page 158: ...1 4 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 182: ...3 16 TROUBLESHOOTING TABLES ...
Page 184: ...4 2 UHF2 PCB SCHEMATICS PARTS LISTS ...
Page 200: ...iv ...
Page 204: ...1 4 MODEL CHART AND TECHNICAL SPECIFICATIONS ...
Page 228: ...3 16 TROUBLESHOOTING TABLES ...