- Printers
- Laser printer
size-mismatch
Brother MFC-L8900CDW: Size Mismatch
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
High
Quick answer
Brother defines “Size Mismatch” as: The loaded paper size differs from the tray’s configured size. That message alone does not prove a replacement part. The next useful discriminator is tray setting, measured sheet dimensions and the size requested by the job.
Safety first
Stop and check this first
- Use only media and sizes supported by the selected tray and duplex path.
Safe checks you can perform
- Preserve the exact display and context
- Run one controlled owner-safe discriminator
- Stop at the proved owner/service boundary
Leave these tasks to a qualified professional
- Do not attempt this professional task: Measured handoff for Size Mismatch
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Measured handoff for Size Mismatch
What they doCompare job ticket, tray settings and measured sheet, then test the relevant size/type sensors and registration timing before replacing hardware.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Preserve the exact display and context
Photograph “Size Mismatch”, including any tray, color or ## suffix. Save model/region, page count, supplies-life page, job/media and the last intervention before clearing it.
Use only media and sizes supported by the selected tray and duplex path.
Evidence: Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
Run one controlled owner-safe discriminator
Record the job-requested size/type, tray-configured size/type and actual sheet dimensions/media. Correct only the mismatched layer and retest one sheet. Record tray setting, measured sheet dimensions and the size requested by the job; change only one variable before retesting.
Use only media and sizes supported by the selected tray and duplex path.
Evidence: Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
Stop at the proved owner/service boundary
A mismatch between those three values is configuration/media, not hardware. If all agree and the message repeats, service the size/type sensing and registration branch.
Use only media and sizes supported by the selected tray and duplex path.
Evidence: Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Printers
- Brand
- Brother
- Product type
- Laser printer
Known code variants
- Brother Format incorrect
- Brother Format stimmt nicht
- Brother Formato non corrispondente
- Brother Size Mismatch
- Brother Tamaño no coincide
- Format incorrect
- Format stimmt nicht
- Formato non corrispondente
- MFC-L8900CDW Format incorrect
- MFC-L8900CDW Format stimmt nicht
- MFC-L8900CDW Formato non corrispondente
- MFC-L8900CDW Size Mismatch
- MFC-L8900CDW Tamaño no coincide
- Size Mismatch
- Tamaño no coincide
What it means
Official meaning: The loaded paper size differs from the tray’s configured size. Decision boundary: record tray setting, measured sheet dimensions and the size requested by the job. Service or purchase proof: Compare job ticket, tray settings and measured sheet, then test the relevant size/type sensors and registration timing before replacing hardware.
Warnings and stop conditions
- Mediumsource verified
Use only media and sizes supported by the selected tray and duplex path.
Evidence: Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
Symptoms and causes
Probable causes · in order
- What the Brother message establishesConfirmed
The official Brother MFC-L8900CDW family guide defines “Size Mismatch”: The loaded paper size differs from the tray’s configured size.
Evidence: Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
- The observation that changes the next branchPossible
Capture tray setting, measured sheet dimensions and the size requested by the job. A mismatch between those three values is configuration/media, not hardware. If all agree and the message repeats, service the size/type sensing and registration branch.
Evidence: Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
Virtual technician
Does size-mismatch still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Brother MFC-L8900CDW Online User's Guide - error and maintenance messages
Brother Industries, Ltd. · 2021 · official_doc
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