Chapter 7 Basic Troubleshooting; Introduction; Accessory Connectors; 20-Pin Accessory Connector - Motorola PM1200 Basic Service Manual

Chapter 7 Basic Troubleshooting

7.1

Introduction

This chapter contains troubleshooting charts which can help isolate a problem to the board level.
Board-level troubleshooting does not attempt to isolate problems to the component level.
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C a u t i o n
7.2

Accessory Connectors

7.2.1

20-Pin Accessory Connector

A 20-Pin accessory connector is located on the rear of the transceiver. External TX audio line input,
PTT (Push To Talk), Squelch, and external RX audio line output signal may be obtained from this
connector for use with data transmission/ reception modem and other accessories.

Figure 7-1. Transceiver Rear Accessory Connector Pin Configuration

When performing both transmit and, especially, receive tests, it is still
possible that equipment might be damaged by the radio transmitter. Besides
a possible radio failure, the radio might also transmit while in receive under
the following conditions: trunking-mode affiliation, missing emergency
jumper, a defective PTT button, or other unintentional PTT activations.
With the exception of some inputs on service monitors, a suitable attenuator
rated at 100 W or more should always be used with all test equipment
connected to the RF connector.
Accessory 16/20-Pin Connector
20 2 4
3
19 1
1 - SPEAKER
2 - EXT_MIC_AUDIO
3 - DIG_IN1 (Data PTT)
4 - DIG_OUT2 (EXTERNAL ALARM)
5 - FLAT_TX_AUDIO
6 - DIG_IN3 = Sel5/MDC
7 - GROUND
8 - DIG_IN_OUT_4 = Sel5/MDC
9 - DIG_IN5 WITH WAKEUP (EMERGENCY)
10 - DIG_IN6 WITH WAKEUP (IGNITION)
11 - FLAT/FILTERED_RX_AUDIO
12 - DIG_IN_OUT_7
13 - SWB+
14 - DIG_IN_OUT_8
15 - RSSI
16 - SPEAKER+
17 - BUS+
18 - BOOT_CNTRL
19 - N.C.
20 - N.C.
6 8 10 12 14 16 18
5 7 9 11 13
15 17