Direct answer
For the Canon imageCLASS MF455dw, local scanner operation, connection, driver/app, permissions and destination storage should be separated. First, start a scan from the printer panel where supported.
What this covers
- Canon imageCLASS MF455dw (5161C005)
- Canon printer; PIXMA/MegaTank/MAXIFY/imageCLASS ink/toner systems and maintenance paths differ.
- The specific fault this record addresses: scanner is not found or scanning fails
What it does not cover
- ×The same symptom on a different Canon product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
The scanner glass or the calibration strip is dirty
What separates it A line down the whole length of every scan, in the same position.
How to confirm A consistent line means something stationary is being scanned repeatedly. Clean the full glass including the narrow strip beside the main glass, which the ADF scans through and which is easy to miss.
- 2
The scan is being started from the wrong end
What separates it Scanning from the printer's panel fails while scanning from the computer works, or the reverse.
How to confirm Scan-to-computer requires a service on the computer that scan-from-computer does not. Trying both directions identifies which path is broken.
- 3
The scan software or driver is not installed
What separates it The printer prints normally but does not appear in any scanning application.
How to confirm Basic print drivers install automatically while scan support often does not. Install the manufacturer's full software package.
- 4
The scan is being saved somewhere unexpected
What separates it The scan appears to complete with no visible file.
How to confirm Check the destination folder configured in the software rather than assuming it failed.
- 5
The scanner lock is engaged
What separates it A new or recently moved unit that grinds or does nothing.
How to confirm Some scanners have a transport lock that must be released before use.
- 6
The resolution requested is too high for the connection
What separates it Scans failing or timing out at very high resolutions and working at lower ones.
How to confirm Very high resolution scans produce large files that can time out over a network connection.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- Whether scanning works from the printer's panel, from the computer, or neither — this identifies which path is broken.
- Whether marks appear in the same position on every scan, which points at the glass rather than the document.
- Whether the printer appears in the computer's scanning application at all.
- Where completed scans are configured to be saved.
Clean the full scanner glass including the narrow calibration strip
ReversibleThe strip beside the main glass is what the ADF scans through, and it is the usual cause of a line down every page.
Try scanning from both the printer's panel and the computer
ReversibleThe two use different paths, and which one fails tells you where the problem is.
Install the manufacturer's full software package
ReversiblePrint drivers install automatically far more often than scan support does.
Check the configured save destination
ReversibleA scan that appears to fail has often completed into a folder nobody looked in.
Scan a blank white sheet to characterise marks
ReversibleIt makes glass contamination and sensor faults immediately visible.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- 5161C005. Canon printer; PIXMA/MegaTank/MAXIFY/imageCLASS ink/toner systems and maintenance paths differ.
- Type — MONOCHROME LASER all-in-one (toner)
- A black-and-white laser AIO (scan/copy/fax, duplex, wireless) — prints only in BLACK by design, for fast, low-cost text. Laser uses toner and does not clog from disuse.
- Toner & drum
- Faded print is low/unseated toner; streaks/repeating marks are toner or drum. No colour because it is a mono printer.
- Connectivity
- Wi-Fi/Ethernet/USB; 'offline' is usually a network/queue issue.
- Symptom boundary
- This record covers Canon imageCLASS MF455dw when it scanner is not found or scanning fails. A different symptom on the same hardware, or this symptom on a different Canon product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Stop for cracked scanner glass, liquid inside the unit, or a carriage that grinds when it moves.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. Canon publishes this as "Unable to scan through network connection after windows 10 update (MF Scan Utility Models)". Canon's article for a scanner that stops being found over the network and the scan utility failing. Probed 2026-08-21: title-verified. What that article does not carry is the model boundary — it is written for a product line, and 5161C005 is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
My Canon imageCLASS MF455dw won't print colour documents in colour.+
It cannot — the MF455dw is a monochrome (black-and-white) laser, so it prints everything in black/greyscale by design; there is no colour toner. That is not a fault or a setting. If you need colour, a colour laser (like the MF656Cdw) or a colour inkjet is required. For high-volume, low-cost black text and documents, the mono laser is fast and economical.
Every scan has a line down it in the same place.+
Something stationary is being scanned over and over, which means the glass rather than the document. Clean the whole glass — and specifically the narrow strip of glass beside the main scanning area, which is what the document feeder scans through. That strip is easy to overlook and is the usual culprit when the line appears on feeder scans.
The printer prints fine but doesn't show up for scanning.+
Print drivers install automatically in a way that scan support often does not, so you have print capability without scan capability. Install the manufacturer's full software package for your exact model rather than relying on the driver the operating system added by itself.
Does this answer apply to every Canon model?+
No. It is scoped to 5161C005. Canon printer; PIXMA/MegaTank/MAXIFY/imageCLASS ink/toner systems and maintenance paths differ.
What should I record before troubleshooting scanner not found or scan failed?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing scanner not found, scan failed. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Protect private documents and do not grant broad folder access unnecessarily.
Answer for the exact device and software version shown above.