Riso Error A16-525 [better] ✦

The A16-525 error on a Riso duplicator indicates a "Master Disposal Jam" or a failure in the master disposal compression mechanism. Essentially, the machine tried to discard a used master into the disposal box, but it got stuck or the compression plate failed to move correctly. Quick Fixes to Try First

Empty the Disposal Box: The most common cause is a full master disposal box. Pull out the box, discard the used masters, and ensure it is pushed back in completely until it clicks.

Check for Stuck Masters: Look inside the disposal area for any "bird-nested" or crumpled masters that didn't make it into the box. Carefully remove any loose scraps of master material.

Reset the Machine: Open the front cover, turn the power switch OFF, wait 10 seconds, and turn it back ON. Sometimes a simple power cycle clears the sensor logic. Deeper Troubleshooting

If the error persists after emptying the box, the issue may be mechanical:

Disposal Compression Plate: Inside the disposal unit, a plate compresses the masters to save space. If this plate is stuck or its home-position sensor is dirty, the A16-525 error will trigger.

Sensor Obstruction: A small piece of master paper might be blocking the "Box Full" or "Compression Home" sensor. Use a can of compressed air to gently blow out dust from the disposal assembly.

Master Stripper Guide: Check the area where the master is pulled off the drum. If the stripper guide is dirty or bent, it won't "hand off" the master to the disposal unit correctly. How to Clear the Code (Maintenance Mode)

If you have cleared the jam but the code won't go away, you may need to reset it manually: Hold down the Reset key while turning the power ON. Continue holding until the display initializes.

If your model uses Test Modes, entering Test Mode 080 (Clear All Errors) may be necessary, though this is usually reserved for technicians.

Pro Tip: To prevent this in the future, avoid letting the disposal box get 100% full. Emptying it at the start of every long print job prevents the "backlog" that causes these mechanical jams. riso error a16-525

Does the error happen immediately when you turn the machine on, or only when you try to create a new master?

The Riso error A16-525 is a common "service call" code on Risograph digital duplicators, typically indicating that the machine is awaiting master removal from the print cylinder. While it primarily signals that a used master is still attached to the drum when the machine expects it to be gone, it often appears as a "false" error even when no master is present. Common Causes of Error A16-525

Physical Obstruction: A used master master is actually stuck on the drum or failed to eject into the disposal box.

Sensor Misreading: The machine uses an optical sensor to detect masters. If the sensor is dirty or blocked, it may falsely report a master is present.

Aftermarket Screens: Non-original "generic" silkscreens often use white plastic mesh. The sensor's light reflects off this mesh, tricking the machine into thinking a master is still attached.

Damaged Light Absorber Strip: 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.

Drum Angle Misalignment: 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

First, physically remove the drum and verify there is no master attached. Check the master disposal unit for jams or broken transfer belts, which can prevent the master from leaving the drum area. 2. The "Sharpie Trick" (For False Errors)

If the error persists on a clean drum, it is likely an optical detection issue.

Clean the Absorber Strip: Wipe the small black velvet strip (usually near the clamp) with a dry cloth to remove paper dust. The A16-525 error on a Riso duplicator indicates

Darken the Strip: 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.

Gaffer Tape: 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 physical cleaning doesn't work, you may need to clear the machine's state:

Riso rz300ep: error a16-525 - Конференция StartCopy

The Riso error code indicates the machine is Waiting for the master to be removed from the print cylinder (drum)

. This error occurs when the master sensor detects a master (or a reflection it interprets as one) still attached to the drum when it should be clear. Primary Troubleshooting Steps Manually Remove the Master : If a master is actually on the drum, remove it by hand. Clear the Disposal Box

: Ensure the master disposal box is empty and correctly seated. Clean the Master Sensor

: Wipe the sensor (located above the drum area) to remove any ink or dust that might be causing a false reading. Troubleshooting "False" Errors

If the error persists even when there is no master on the drum, try these common community fixes: Darken the "Light Absorber Strip"

: The sensor works by shining light on a small black velvet or felt strip to the right of the clamp. If this strip is worn, fuzzy, or reflected, the sensor thinks a master is present. black Sharpie to darken the strip or apply a piece of black gaffer tape or washi tape over it to absorb the light. Check Drum Position You will need isopropyl alcohol and a lint-free

: If the drum isn't returning to its exact home position (Position-A), the sensor may miss the absorber strip. Test Mode Adjustment : Some technicians use Test Mode (e.g., code

) to slightly adjust the drum angle compensation to help the sensor align with the strip. Screen Issues

: If you recently replaced the drum's silkscreen with an after-market version, the white plastic mesh may be more reflective than the original metal mesh, confusing the sensor. How to Reset the Error Basic Reset : Press the yellow button on the panel. Power Cycle

: Turn the machine off, remove the master disposal box, and turn the machine back on. Test Mode Reset

: For some MZ models, you can clear error logs in Test Mode (holding Reset + Stop while powering on) and using specific simulation codes like to reset the system.

steps for your particular Riso model (e.g., RZ, EZ, or MZ series)?

3. Initial User-Level Checks (No Tools Required)

| Step | Action | What to look for | |------|--------|------------------| | 1 | Power cycle the machine completely. | Wait 30 seconds after power off before restarting. | | 2 | Open front cover and check for jammed paper near drum area. | Remove any scraps, especially near sensors on left/right sides. | | 3 | Remove and reseat the error-indicated drum unit. | Pull drum out halfway, push back in firmly until it clicks. | | 4 | Check drum lock lever is fully closed. | Loose drum lock will misalign home sensor reading. |

Step 2: Clean the Sensor and Contact Points

This is the most common fix for error 525.

1. You will need isopropyl alcohol and a lint-free cloth or cotton swab.
2. Clean the Cartridge Chip: Gently wipe the metal contact area on the ink cartridge.
3. Clean the Printer Contacts: Look inside the slot where the ink sits. You will see small metal spring-loaded pins. Clean these gently with a cotton swab dipped in alcohol. Ensure they are not stuck down with ink sludge.
4. Clean the Ink Cylinder Sensor: Depending on your model, there is often an optical sensor near the mouth of the drum. Wipe away any excess ink splatter in that area.

Preventing A16-525 from Returning

Once you have cleared the error, you want it to stay away. Implement these three maintenance habits:

1. Weekly Sensor Cleaning: Add the PF Register Sensor to your weekly cleaning roster. It takes 2 minutes but prevents 90% of A16 errors.
2. Roller Rejuvenation: Use a rubber roller restorer or wash the PF rollers with mild soap every 50,000 prints.
3. Paper Quality Matters: Cheap, dusty paper leaves microscopic calcium carbonate powder on the sensor lens. Use paper designed for high-speed inkjet presses.

Step 2: The "Sensor Check" via Service Mode

You need to verify the sensor is working electronically.

1. Enter Service Mode (Usually: Hold Stop + Start while turning on the power, or press Reset then Numeric 7 – check your specific model).
2. Navigate to I/O Check Mode -> Input Check.
3. Find the code for the PF Register Sensor.
4. Place a piece of white paper at the sensor location. The display should toggle between "0" (no paper) and "1" (paper present).
5. If the value does not change even after cleaning, replace the sensor.

Step 2: Inspect Physical Components

• Home position sensor – Located near the rear frame of the drum housing. Clean with compressed air or lint-free cloth. Look for bent pins or broken plastic.
• Encoder disc – On drum shaft rear side. Check for cracked, oily, or missing timing marks.
• Drive belt – From main drive motor to drum gear. If belt slips or teeth are worn, timing is lost → A16-525.