Lexmark Optra C Service Manual page 120

5045-001
When the printer is turned ON, or the density adjustment panel is
not operated for at least 30 seconds, it enters the OFF state. When
OFF, the COLOR SELECT LEDs go OFF and only the Density
gauge DEFAULT LED (middle) lights if all the colors are set at the
factory-shipping value, or otherwise all LEDs will go OFF. If only the
+ and - keys are pressed for at least 5 seconds, all color densities
are initialized to DEFAULT and the panel enters the OFF state.
If the individual color densities are changed from the default position,
these values will Not be lost when the printer is turned off. They
must be manually set back to the default value.
Test Pattern Selection
1. Press the ENTER key 8 times while holding down the COLOR
SELECT key. All COLOR SELECT LEDs flash to indicate the
shift to the test print pattern setting mode:
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