Motorola CP160 Detailed Service Manual page 47

Troubleshooting Tables for Board and IC Signals (includes Controller, DC Regulation and Audio)
IC Designator
U451
ASFIC_CMP
U480
Dual Opamp
U490
Audio Power Amp
U510
Dual Opamp
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.
4. Voltages are identical for VHF and UHF models unless otherwise indicated.
Pin Pin Function
38 GCB5 general purpose output
39 RX audio send to option
40 Modulation output
41 RX audio out to power amp
42 Flat TX audio return from option
43 RX audio return to option
44 Flat TX audio send to option
45 Vdd for audio path I/O filters
46 Mic audio input
47 Ground for audio path I/O filters
48 Ext mic audio input (not used)
1 Unit 1 output
2 Unit 1 (-) input
3 Unit 1 (+) input
4 Ground
5 Unit 2 (+) input
6 Unit 2 (-) input
7 Unit 2 output
8 Vcc
1 Enable/shutdown
2 Bias reference
3 (+) input
4 (-) input
5 (-) output
6 Vcc
7 Ground
8 (+) output
1 Unit 1 output
2 Unit 1 (-) input
3 Unit 1 (+) input
4 Ground
5 Unit 2 (+) input
6 Unit 2 (-) input
7 Unit 2 output
8 Vcc
DC Voltage Comments (Condition)
0
1.48
1.50 To U201-10
1.51
0.20
1.50
1.50
3.00
1.50
GND
0
2.48
2.48
2.46
GND
0.28
0.29
0
4.96
0.12 (Unsquelched)
3.26 (Unsquelched)
3.26 (Unsquelched)
3.27 (Unsquelched)
3.25 (Unsquelched)
7.48 (Unsquelched)
GND
3.29 (Unsquelched)
1.75
1.56
1.55
GND
1.55
1.56
1.38
4.96
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