The issue of a vertical line appearing only during copying and scanning isolates the problem to the scanner assembly of the all-in-one printer. Since printing from a computer and receiving faxes works correctly, the core printing components (drum, corona wire, fuser) are functioning properly. A vertical line on a scanned or copied page is a classic symptom of debris, such as dust, ink, or a smudge, on the scanner glass. When using the automatic document feeder (ADF), this debris is often located on the small, separate strip of glass that the paper passes over, which translates into a consistent vertical line on the resulting digital image.

A. The pickup rollers: Faulty pickup rollers are responsible for paper handling and would cause paper jams or misfeeds, not lines on the printed image.

B. The corona wire: A problem with the corona wire, which charges the drum, would affect all print output, including jobs sent from a computer.

D. The drum assembly: A scratch or defect on the photosensitive drum would cause a repeating line or mark on every page printed, regardless of the source.

1. Hewlett-Packard (HP) Development Company

L.P. (2023). HP Printers - A Vertical Black Line Is Printed or Scanned. HP Customer Support - Knowledge Base

Document ID: c06563199. The document states

"Vertical lines on copies

faxes

or scans are caused by debris on the scanner glass

scanner lid

or in the automatic document feeder (ADF) slot."

2. University of Wisconsin-Madison. (2020). Ricoh Printers - How to Clean the Scanner Glass to Resolve Lines on Copies or Scans. UW-Madison Information Technology

KnowledgeBase

Doc ID: 105111. This guide instructs users that "Lines on copies or scans are caused by foreign material (e.g. dust

paper

staples

etc.) on the scanner glass." It specifically differentiates between the large flatbed glass and the smaller slit glass used by the document feeder.

3. Brother Industries

Ltd. (n.d.). A vertical line appears on my copies and/or faxes. Brother Solutions Center. In their troubleshooting guide

it is noted

"The cause of this issue is usually a small spot of dirt or correction fluid on the scanner glass strip. This affects copies and faxes sent using the Automatic Document Feeder (ADF)."