: Some users find success by placing a small piece of matte black gaffer tape over the strip to improve light absorption. 3. Reset and Service Mode
: If using an aftermarket screen, use a black permanent marker (Sharpie) to darken the entire black strip and the area around it to ensure no light reflects back to the sensor. riso error a16-525
: The machine uses an optical sensor to detect masters. If the sensor is dirty or blocked, it may falsely report a master is present. : Some users find success by placing a
: A used master master is actually stuck on the drum or failed to eject into the disposal box. : The machine uses an optical sensor to detect masters
: If the drum's "Position-A" is slightly off, the sensor may look at the wrong part of the drum (like the metal surface) instead of the black absorber strip. Troubleshooting and Fixes 1. Immediate Physical Check
: There is a small black velvet strip on the drum meant to absorb sensor light. If this strip is worn, dusty, or missing, the sensor detects reflection from the metal drum instead.