Riso Error A16-525 < Quick | Workflow >

Use this for social media or an internal IT log.

Headline: 1 Star. Would not recommend.

Review: "I’m giving the A16-525 error a solid 1 out of 5 stars. It has a knack for appearing 5 minutes before a print run starts. The suspense of waiting to see if the drum motor will actually unlock is the only excitement in my day. If you enjoy panic attacks and cryptic error codes, this is the feature for you. Otherwise, keep your machine lubricated and pray."

If you are using a refilled cartridge:

If you have more details about the machine model or additional context about when the error occurs (e.g., during a specific operation), I might be able to provide more targeted advice.

"RISO Error A16-525" – What It Means & What to Do

Error A16-525 on a RISO printer typically points to a communication issue between the master-making section and the drum unit, often related to the thermal head or its connection.

Possible causes:

Quick steps to try:

📌 For service manuals or part replacements, refer to your RISO model (e.g., RZ, RP, or SF series).

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) riso error a16-525

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.

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

To understand A16-525, you need a basic understanding of the RISO ComColor’s paper path. These machines run at speeds up to 150 pages per minute. To achieve that speed, timing is measured in milliseconds.

The "A16" family of errors relates to the PF (Paper Feed) Drive Unit. The sub-code "525" points specifically to a Register Sensor timing failure. Use this for social media or an internal IT log

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 error A16-525.

What the machine thinks: “I sent the paper. I waited for the sensor to trigger. The sensor did not trigger within the allowed window. Either the paper didn’t arrive, the sensor is lying, or the roller is slipping.”

Use this if you found a PDF or website that helped you solve it.

Headline: This manual saved me hundreds on the A16-525 error.

Review: "If you are getting the A16-525 code, do yourself a favor and download this guide. The official documentation was vague, but this manual walked me through the drum motor diagnostics step-by-step. I was able to clear the jam and reset the machine in under 20 minutes. A lifesaver for anyone managing their own Riso maintenance."

You are a competent operator, but some repairs are beyond user level. Call a professional if:

Warning: Attempting to disassemble the PF drive unit without the service manual can knock the main timing off permanently, leading to costly head strikes.

If the problem persists, check if there are any firmware updates available for your Riso duplicator. Additionally, have a professional inspect the control board for faults. "RISO Error A16-525" – What It Means &