"Slit glass on left of ADF isn't clean" message Follow
Problem
"Slit glass on left of ADF is not clean" message even though it has been cleaned.
Solution
Set ADF line detection (front side) and line detection (back side) to Mild by performing the following steps
1. Select Utility/Counter
2. Press Stop 00, Stop 01
3. Select ADF Adjustment
4. Select Line Detection (front side) and change to "Mild"
5. Select Line Detection (back side) and change to "Mild"
6. Exit Service Mode