This is the most common fix for error 525.
Many users report this error even when the drum is visibly clear. This typically happens for several reasons: Sensor Misreading (Reflection Issue)
: A piece of the previous master is still physically stuck on the drum or caught in the master clamp.
Riso Error A16-525 typically indicates that the machine is "Waiting for the master to be removed"
Clean the on the drum. Use a dry cloth or a slightly damp one to remove paper dust or ink buildup that might be making it reflective. 3. The "Black Marker" or Tape Trick
