The Riso error signifies that the machine is "Waiting for the master to be removed" from the print cylinder (drum). This usually occurs when the sensor detects a master still attached to the drum after a disposal cycle or fails to recognize that a master has been removed. Common Causes
Try holding the yellow Reset button while turning the machine on to force a clear of the current state. riso error a16-525
RISO rollers are made of a special rubber compound. After hundreds of thousands of prints, this rubber hardens or glazes over. If the paper feed roller slips—even by a millimeter—the paper arrives late at the register sensor. The Riso error signifies that the machine is
Here is the technical translation: The machine expects the leading edge of the paper to hit a specific optical sensor (the PF Register Sensor) at a precise moment during the feed cycle. When the CPU compares the actual sensor activation time against the calculated standard value, if the deviation exceeds the allowable range (usually ± a few milliseconds), the system throws . RISO rollers are made of a special rubber compound
If the optical fix fails, the issue may be mechanical or require a software adjustment: Check the Clamp Area