Diagraph PA/4000, Руководство по обслуживанию, Страница: 155 / 213

Technician’s Guide 2-11
The stepper motor is a 6V DC stepper motor designed to pull media through the PA/4000. If
problems occur that you feel are related to the stepper motor, first check for a jam in the
PA/4000 on both the media side and the mechanical drive side of the PA/4000 center plate.
The motor is connected to the control board at J9. U26, which is not easily replaced, contains
the drive transistors for the stepper motor. In most any case, replacing the entire control board
and/or motor if you suspect problems, is the most efficient way to go.
LABEL LOW SENSOR
The Label Low sensor, located behind the label inner guide disc, sends a signal to the applicator
logic board when the label stock falls below a certain level. The inner guide disc has a notch
that allows the Label Low sensor to reflect off the label stock. When the label stock depletes
below the sensor, it can no longer be sensed.
When the Label Low condition occurs, the Label Low sensor sends a signal to the applicator
logic board.
The applicator board will:
• light the yellow Warning Tower light.
• light the yellow Label LED to begin flashing.
The display will read “Label Low.”
RIBBON LOW SENSOR (FUTURE FEATURE)
The Ribbon Low sensor is an opposing beam sensor located on a bracket mounted on the print
engine behind the ribbon supply spindle. One end of the bracket contains an infrared LED.
The other end holds a photo-transistor.
When a full ribbon roll is placed on the ribbon supply spindle, the beam is broken. When the
ribbon level depletes to a certain level, the LED and photo-transistor re-connect to make the
beam. The sensor then sends a signal to the applicator logic board.
The applicator logic board will:
• light the yellow Warning Tower light.
• cause the yellow Ribbon LED to begin flashing.
The display will read “Ribbon Low.”
Ribbon Out Sensor
The Ribbon Out Sensor, located on the print engine above the rear drive roller is commonly
used for direct thermal printing.