Intermec EasyCoder 501 XP & 601 XP – Service Manual
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Chapter 8 Print Unit
8.8 Headlift Sensor
Description (EasyCoder 501 XP and 601 XP)
The purpose of the headlift sensor is to detect whether the print-
head is raised or lowered. To avoid the risk of overheating the print-
head dots, printing can not be performed when the sensor detects
that the printhead is raised (the media serves to cool the printhead.)
An ever so slightly raised printhead would also impair the print-
out quality. Thus, it is important that the printhead is properly low-
ered and a suffi cient pressure is applied before the sensor detects a
“Closed” condition.
The photoelectric sensor is attached to the electronics compart-
ment side of the inner print unit gable by means of two #T10
Torx screws. When the printhead is raised, a beam of light is inter-
rupted by an arm connected to the headlift shaft. This is detected
by the fi rmware 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 suffi ciently or if the arm is not fi tted in the correct angle,
a malfunction will occur.
Adjusting the Sensor Arm (EasyCoder 501 XP and 601 XP)
• Perform an adjustment of the printhead pressure as described in
Chapter 8.9.
• Without switching off the power, remove the cover over the
electronics compartment (see Warning notice.)
• Place a 1 mm (0.04 inches) thick plastic card between the print-
head and the platen roller and lower the printhead.
• 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 posi-
tion 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.
Sensor Arm
Headlift Shaft
#T10 Torx Screw
Sensor
“Printhead Closed” position
“Printhead Open“ position
WARNING!
The electronics compartment contains
wires and circuits with dangerous
voltage (380V).
Take precautions to avoid short circuits
and electrostatic discharges.
