Unit 6: Maintenance
CT4i Series Operator Manual 6-7
CLEANING THE SENSOR
The gap sensor is used to control the positioning of the label. It is a transmissive see-thru sensor that
detects the edge of the label by sensing through the backing paper which is translucent and detecting
the presence of the opaque label.
So when dust, dirt or other foreign matter interferes with the light path of the sensor, erratic label
positioning occurs. The sensor should thus be cleaned regularly, after every two rolls of labels.
1. Turn the printer OFF and remove the power cable.
2. Open the Top Cover.
3. Locate the sensor located next to the yellow screwdriver, near
the left-hand side label guide so that it moves whenever the
Label Guide are adjusted for different media widths.
4. Apply Thermal Print Head Cleaner to a cotton swab.
5. Use the cotton swab to clean any foreign matter from the
exposed surface of the sensor by inserting the cotton tip in the
paper slot and briskly cleaning it with a back and forth motion.