Cleaning Liquid sensor

The Liquid sensor on the Processing unit has to be checked on regular base and cleaned if necessary.

1. Remove the silicone tube (circled in red) from the middle slot of the Liquid sensor. Check the outside of the tube and check each slot closely to ensure no white substance or dust is blocking the LEDs. If cleaning is needed, continue with step 2.
2. Clean the tube near the Liquid sensor with De-ionized water and dry with canned air or a gauze pad.
3. Remove the drip tray under the needle.
4. Use a soft fine bristle toothbrush to remove any foreign particles in front of the sensor LEDs. Brush up and down in the slots on the left and right side of the tube space (shown in red circles).
   
5. Replace the silicone tube into middle slot of Liquid sensor and test under Maintenance - Check sensors-Check Liquid Sensor-Test. The Rinse and Drain should show two blue check marks.