Ribbon Sensor - Intermec EasyCoder PX4i Service Manual

7.4 Ribbon Sensor

Description
Replacement
EasyCoder PX4i and PX6i Service Manual
The ribbon sensor is fi tted to the center section from the media compart-
ment side and is partly enclosed by the ribbon supply unit (see Chapter
7.2). The sensor consists of a plastic housing with a LED and a photoelec-
tric sensor plus a cable.
The light from the LED is intermittently blocked by the saw-toothed edge
of the rotating code disc. The signals from the sensor allow the fi rmware
to detect the speed with which the bobbin rotates and compare it with
the speed of the media feed. Thus, both "out of ribbon" and "ribbon low"
conditions can be detected.
If no bobbin rotation is detected during media feed, the Fingerprint
fi rmware assumes an error condition (error 1027 "Out of transfer ribbon")
provided the printer is set for thermal transfer printing. In IPL, the error
message "Ribbon out" is displayed.
The ribbon sensor is connected to J56 on the CPU board (see Chapter
15.3).
Ribbon supply unit
• Remove the cover over the electronics compartment as described in
Chapter 3.3, taking all precautions against electric shock.
• Remove any transfer ribbon from the ribbon supply unit.
• Remove the ribbon supply unit as described in Chapter 6.2.
• Disconnect the sensor's cable from J56 on the CPU board.
• Remove the #T10 Torx screw that holds the sensor to the center section.
• Install a replacement sensor unit in reverse order.
Chapter 7 — Transfer Ribbon Mechanism
Ribbon sensor
#T10 Torx screw
57