Troubleshooting; Introduction - Harris DX 25U Technical Manual

Introduction

6.1
This section of the technical manual contains troubleshooting
procedures for the DX-25U.
Problems that could cause an OFF AIR situation and how they
relate to the front panel ColorStat™ indicators, including over-
loads and interlocks will be discussed first.
This section is a troubleshooting guide for the transmitter as a
system. For additional information related to an individual mod-
ule or board, refer to the section of the manual for that particular
board.
Section VI

Troubleshooting

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Symptom: Transmitter will not turn ON - No ColorStat™ panel indicators are illuminated.. . . . . . . . . . . . . . . . . 6-6
Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Loss of AC Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Loss of +5V Supply on LED Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Loose Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Symptom: Transmitter will not turn on - all ColorStat™ panel indicators are illuminated Green. . . . . . . . . . . . . 6-6
Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
+5B Circuit Not Up To Operating Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Contactor Turn On Logic On The Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Contactor Drive Circuitry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
+30 VDC Feedback Auxiliary Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
240 VAC Coil Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Open Contactor Coil On K1 or K2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Symptom: Transmitter will not turn on - one or more ColorStat™ panel indicators are illuminated RED. . . . . . 6-7
Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Symptom: Transmitter will turn ON but immediately turns OFF - one or more ColorStat™ panel indicators illumi-
nate RED. The transmitter may try to turn on twice and a fault indicator illuminates AMBER then RED.. . . . . 6-7
Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Symptom: Transmitter turns On (LOW, MEDIUM or HIGH buttons illuminate) but there is no power output and
no PA current is indicated. Supply voltage is indicated on the multimeter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
PA Turn-Off Command Given To Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Type 4 or Type 5 Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Power Output Is Set To Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Symptom: Transmitter is running, but power is lower than normal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Possible Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Power Reduction Circuitry Activated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Symptom: Unable to raise power past a certain point. ColorStat™ panel ANT and/or FILTER LED indicate RED. . 6-8
Possible cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Symptom: Unable to raise power past a certain point. No ColorStat™ panel indicators Illuminated RED. . . . . . 6-8
Possible cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Analog Input Board maximum power adjustment R27 misadjusted or defective. . . . . . . . . . . . . . . . . . . 6-8
Analog Input Board, half power step up circuit may have failed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
PA Turn on/Turn Off control signals on Modulation Encoder A37 may be incorrect.. . . . . . . . . . . . . . . 6-8
Open fuses on Fuse Boards A24 or A25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Symptom: Transmitter turns ON (Low, Medium, or High Indicators Illuminate) but will not modulate. . . . . . . . 6-8
Rev. R: 11-11-96
Table 6-0. Troubleshooting the Transmitter
888-2297-002
WARNING: Disconnect primary power prior to servicing.
This section contains techniques and guidelines to assist the
engineer in isolating the problem more quickly. The engineer
using this section of the manual must have the proper test
equipment available and has a good working knowledge of the
transmitter and the operation of the individual modules and
boards.
Section VI
Troubleshooting
6-1