Reference the below video for instructions to clean the i3300 printer.
i3300 Sensor Locations
The notch sensor is used to maintain calibration with notched labels (indentations cut into the side of the liner), the ramp sensor maintains calibration with gapped labels (die cut labels with gaps in between each label on the liner), the leading edge sensor detects the front edge of the label media. The front edge sensor aids in reducing label waste, and also detects if the media has been fed correctly along the label path. These sensors can be cleaned with 90% rubbing alcohol and compressed air. Reference page 29 of the i3300 user manual (attached) for complete cleaning instructions.
Cleaning the Front Edge Sensor
Adhesive residue and label debris can accumulate on the leading edge sensor. This sensor is located in the cutter chute, and can be difficult to identify unless the cutter is disengaged. The sensor in the cutter isn't entirely covered by the clear plastic cover. If you look through the exit chute of the printer you can see the plastic cover is open to the front of the printer, so dust can settle in that sensor and be difficult to remove. Compressed air can be used to dislodge dust and debris.
Note: You may need to turn the printer on its back to view and clean the entire Leading Edge Sensor.
90% rubbing (isopropyl) alcohol can be used to break down adhesive residue. This image shows the leading edge sensor area (back side) with adhesive buildup.
