Troubleshooting Guide; Table 5.5 Troubleshooting - ILX Lightwave LDC-3926339 User Manual

Troubleshooting Guide

This section is a guide to troubleshooting the LDC-3926339. Some of the more
common symptoms are listed here, and the appropriate troubleshooting actions
are given. If problems persist, contact ILX Customer Service (see page xii for
contact information). Also check the www.ilxlightwave.com Support page, and the
Library page for Application Notes and Technical Notes.

Table 5.5 Troubleshooting

Symptom
LDC-3926 Series unit will not power up
Power on, but outputs have been shut off.
Instrument may be locked up or instrument
resets itself.
Power on, but no current output
Unable to adjust output
Output current is at limit and cannot be lowered
Output goes off intermittently
Unable to adjust output
Power Mode operation has high output current,
but little or no power is measured
02_03
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C A L I B R A T I O N A N D T R O U B L E S H O O T I N G
Corrective Action
Check AC Power line voltage and power cord
•
connection.
This may occur if the instrument loses power (AC line)
•
briefly or line voltage drops below specification. If
instrument is "locked up", power it off and then on to
restart.
Check Interlock pins on LASER input connector on
•
instrument rear panel. These pins must be shorted
either directly or through a switch. The front-panel
Laser Enable key switch should also be on.
If OPEN CIRCUIT is indicated (E403 or E503), check
•
the load connections and cable and then try again. Be
sure the cable connector is securely fastened to the
back of the module(s). Also check that the Voltage
Limit setting is above the laser's operating voltage.
Check the OUTPUT ON soft key. It should read ON.
•
Check the instrument mode, the channel number, and
the laser current limit.
If IPD or PPD mode is used, check the monitor diode
•
(feedback) connections. Check the monitor
photodiode connections. Also check if the photodiode
bias is off.
Check the interlock circuit. An intermittent interlock will
•
turn the output off.
Make sure the AC power cord connection is secure.
•
Power-line drop-outs may reset the unit and when
power is restored, the output will be off.
Check the output cabling. A laser open circuit will
•
disable output.
Make sure that the ISET adjust parameter is
•
highlighted.
Check the I LIMIT parameter; it should be set above the
•
laser operating current.
Check the VLIMIT parameter, the voltage limit should
•
be set above the voltage condition of your laser load.
Check the photodiode bias. If it is off, the circuit may
•
act as an open feedback loop. Set the bias to on (5V).
Troubleshooting Guide
LDC-3926339
5
C H A P T E R
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