Inspect the optical cassette on Fuse 1 generation printers after every print. If the optical cassette is contaminated, clean it before the next print.

To remove the optical cassette:

1. Put on a new clean pair of nitrile gloves. Powder, skin oils, and other contaminants may smudge the glass windows in the optical cassette.
2. On the touchscreen, drag the Unlock Door slider. The print enclosure door unlocks.
3. Open the print enclosure door.

4. On the ceiling of the print enclosure, loosen the thumb screw in the front-center of the printer cavity. The cassette tray swings down.

5. Slide the optical cassette out of the cassette tray. Set the optical cassette aside on a clean, flat surface with the gasket facing upward. Ensure that nothing is directly touching either glass window of the optical cassette.
6. If the optical cassette is dirty or contaminated, clean or replace it.

To insert the cleaned optical cassette:

1. Place the clean optical cassette into the cassette tray.

2. Return the cassette tray to its closed position and tighten the thumb screw in the front of the printer cavity.

3. Close the print enclosure door. Press firmly to ensure that the door is fully latched. If necessary, squeeze the front of the door using the cutout on the right side of the printer for leverage.