Ribbon End Sensor - Intermec EasyCoder PC4 Service Manual

4.6 Ribbon End Sensor

Description
Replacement
Intermec EasyCoder PC4—Service Manual
The ribbon end sensor is a photoelectric sensor that detects when the
printer runs out of ribbon. It is only fitted in the TTR model of EasyCoder
PC4. A beam of light is transmitted from an LED (light emitting diode)
and reflected back to a receiver by the silvery foil trailer of the ribbon. The
sensor triggers at 4V.
Note: The Ribbon End Sensor only works if the ribbon has a silver-colored
trailer that can reflect the light.
A DT printer can be set to detect ribbon end, and a TTR printer can be
set to ignore ribbon end, without any error being reported (see ESim v6.xx,
Programmer's Reference Manual, OD command).
Both the emitter and the receiver are fitted on a small printed circuit board,
which is installed in a pocket on the print frame moulding. A cable runs
inside the left-side hinge of the print frame and down to the main board,
where it is connected to JP7. The same circuit board is also used for the
label taken sensor.
Refer to Chapter 5.2 for an description of how to access the main board.
Do not remove the sensor unless you intend to discard it, since you may
damage some of the components when you pull it up.
• Disconnect the cable from JP7 on the main board.
• Remove the cable cover.
• Carefully pry the sensor PCB loose (it may be fitted with a drop of glue)
and pull it straight up using a small pair of pliers while carefully manip-
ulating the cable and connecter through the hinge and out through the
wall of the ribbon supply cavity.
• Install a replacement sensor in reverse order.
Ribbon end sensor
Chapter 4 —Print Fram
25