: The master detection sensor is stationed inside the machine frame, positioned to look directly down at the drum's clamp line.
If the error returns immediately after a reset, a technician should evaluate the following parts:
Sometimes ink mist gets on the master-detect sensor itself (usually located in the master disposal unit area). Gently wipe it with a lint-free cloth.
Underneath the master sheet on the drum cylinder lies a dark, textured area known as the . The optical sensor shines light on this area; if it sees a reflection, it assumes a master is present. If it sees pure absorption (darkness), it knows the drum is empty. If this strip is scrunched up, peeling, or covered in reflective ink, the sensor will throw the A16-525 error even on a naked drum. 4. Recent Screen Replacement Issues
Clean the master clamp plate on the drum itself to ensure it is releasing the stencil cleanly. riso error a16-525
For users of Risograph printers, particularly those in high-volume production, encountering error codes is a standard part of maintenance. However, some codes can be more stubborn than others. is a common, yet often frustrating, error that indicates a master-related issue on the print drum.
If there is no physical master on the drum but the screen still shows the A16-525 code, clear the machine’s temporary memory:
: Turn the power off and back on while holding the Reset key to clear the temporary error state.
If you recently replaced the screen mesh, ensure the alignment is precise and no metal parts are accidentally exposed where they could reflect light back to the sensor. 4. How to Clear a Stubborn Error Loop : The master detection sensor is stationed inside
If there is an actual master stencil jammed inside the machine, follow these sequential steps to safely clear it:
It is highly common for a drum to trigger an A16-525 error when it is completely bare. If you insert a drum and immediately get flagged for a stuck master, use these steps to trace the issue: Step 1: Inspect and Rejuvenate the Black Velvet Strip
If the error persists, you must manually clear the stuck stencil. Open the front cover of the Riso machine. Pull the print drum out using its handle.
If the master screen on the drum is torn or damaged, it can snag the master, preventing removal. Underneath the master sheet on the drum cylinder
Turn off the main power switch. Hold down the yellow Reset button on the control panel while flipping the power switch back on. Keep holding the reset button for 5 seconds to force the machine to reinitialize its mechanics.
Are you using a on this drum, or did the error start after a specific incident like a master jam?
Over time, wet ink or oily residue bleeds onto this black strip. The reflective ink tricks the optical sensor into thinking a light-colored master sheet is still covering it.
Do not wait for the "Disposal Box Full" light to turn on. Empty the master disposal box at the start of every heavy printing shift.
