ZETRON 640 DAPT XTRA, Installation And Repair Manual

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Troubleshooting and Repair
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Symptom Possible Problems Solution
Pager alerts, but display
characters are missing. Insufficient DTMF level Readjust the FROM TEL levels per
Section 6.
Use Table 20 to help isolate and correct problems that may appear with voice paging output from
the Model 640.
The
italicized words in the table are used to guide the system operator to the specific sight or
sound that defines the problem. They allow a quick scan of the table for the appropriate entry.
Table 20. Troubleshooting Voice Paging Output from the Model 640
Symptom Possible Problems Solution
Hum or buzz present during
voice page.
Over deviation Reduce the station VOICE pot setting.
Telco line imbalance Call the telco CO.
Too much background noise
present during voice page.
Overdriving transmitter Reduce the station VOICE pot setting.
Trunk AGC too hot Readjust the FROM TEL levels per Section
6.
Voice quiet at first, then
increases during voice page.
Hybrid not balanced Readjust the BAL R and BAL C levels per
Section 6.
FRONT PANEL LEDS
The front panel lights indicate the status of hardware and software signals in the system. They
can provide valuable information when troubleshooting paging operations. Table 21 outlines the
meaning of the lights labeled LINE, ANS, or ACT which relate to communication between the
CPU and the microprocessor on the peripheral board. As parts of the paging software become
active, the LEDs illuminate in different ways as described below. Also, refer to Section 3 for a
description of each LED.
Table 21. Troubleshooting Front Panel LED Operation
Software Step LEDs Light Activity
Power on all ACT all solid on
Boot-up sequence READY comes on solid at end of cycle - ready for paging
all ACT all solid on, then rapidly blinking until end of cycle
MODEM, COM intermittent flickering throughout cycle
New telco call active trunk (A-D):
LINE
blinks for end-to-end and pulse
on for trunk answer