Headlift Sensor - Intermec EasyCoder 601 XP Service Manual

8.8 Headlift Sensor

CAUTION!
The electronics compartment contains
wires and circuits with dangerous
voltage (380V).
Take precautions to avoid short circuits
and electrostatic discharges.
Intermec EasyCoder 601 XP – Service Manual Ed. 2
Description
The purpose of the headlift sensor is to detect whether the printhead
is lifted or lowered. To avoid the risk of overheating the printhead
dots, printing can not be performed when the sensor detects that the
printhead is lifted (the paper serves to cool the printhead). An ever
so slightly lifted printhead would also impair the printout quality.
Thus, it is important that the printhead is properly lowered and a
sufficient pressure is applied before the sensor detects a "Closed"
condition.
The photoelectric sensor is attached to the electronics compartment
side of the inner print unit gable by means of two #T10 Torx screws.
When the printhead is lifted, a beam of light is interrupted by an arm
connected to the headlift shaft. This is detected by the firmware so
an error message (1022 "Head Lifted") will be returned if you try
to print a label. The headlift sensor is connected to P50 (marked
"HEADL") on the CPU board.
The arm that blocks the light through the sensor is attached to the
headlift shaft by means of a #T10 Torx screw. If the screw is not
tightened sufficiently or if the arm is not fitted in the correct angle,
a malfunction will occur.
Adjusting the Sensor Arm
• Perform an adjustment of the printhead pressure as described in
chapter 8.9.
• Without turning off the power, remove the cover over the
electronics compartment (see Caution notice).
• Place a 1 mm (0.04") thick plastic card between the printhead
and the pressing roller. Close the printhead and the locking arm.
• Loosen the #T10 Torx screw that holds the sensor arm.
• Run the program listed on next page.
• Move the sensor arm from open position towards closed position
until the Error LED goes out, which indicates the correct
position.
• Tighten the screw and check that the arm runs freely inside the
fork-shaped sensor.
• Put back the cover and power cord and turn on the printer.
#T10 Torx Screw
Sensor Arm
"Printhead Closed" position
Chapter 8 Print Unit
Headlift Shaft
"Printhead Open" position
Sensor
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