17
Troubleshooting
a p p e n d i x a
TR O U B L E S H O O T I N G
* To test the data link with an ohm meter, disconnect the link from the controller and mea-
sure the resistance across pins 2 and 3 of the XLR male plug. The reading should be around
120 ohms. Readings from 400 - 20,000 ohms indicate the data link is not terminated. Infi-
nite resistance indicates a bad connection, broken wire, or a defective fixture. Very low
readings indicate a short circuit in the data link or a defective fixture.
problem
probable cause(s)
suggested remedy
None of the fixtures respond
to the controller.
The controller is discon-
nected from the data link.
Connect controller.
Blackout or standby mode
selected.
Press blackout button.
Some fixtures do not
respond, respond erratically,
or continuously reset.
Bad data link connection.
Check data link connections/
cables and correct accord-
ingly.*
DMX signal polarity reversed.
Swap pins 2 and 3. See sec-
tion 2.
DMX signal reflection.
Insert termination plug in the
last light on the link.
Incorrect addressing of fix-
tures.
Check addresses.
Fixtures not on.
Turn on fixtures.
Protocol auto-detection fail-
ure.
Switch the fixtures off and
then back on. In general,
power on the controller
before the fixtures.
Fixtures do not execute pro-
gramming on one or more
channels.
Fader control is overriding
programming.
Turn off fader control.
No light from some or all fix-
tures.
The scenes do not contain
‘Lamp On’ instructions for fix-
tures with remote lamp on/off.
Make sure the “Lamp On”
command is saved in at least
one scene.
Uneven or incomplete fader
control.
Faders not calibrated.
Calibrate faders as described
in “Service”.
2518 IV.BOOK Page 17 Tuesday, September 22, 1998 7:10 PM