Why does my Brother Printer produce a vertical black line in copies?
- SSusan FischerAug 28, 2025
Black vertical lines on copies are typically caused by dirt or correction fluid on the glass strip, or the corona wire for printing is dirty.

Why does my Brother Printer produce a vertical black line in copies?
Black vertical lines on copies are typically caused by dirt or correction fluid on the glass strip, or the corona wire for printing is dirty.
What to do if Brother MFC-7340 All in One Printer says 'Document is too long'?
If your Brother All in One Printer displays 'Document is too long', check if the document is jammed in the ADF (Automatic Document Feeder). If it is jammed, remove it.
What to do if my Brother All in One Printer has no printout?
If your Brother All in One Printer isn't printing, there are several things you can check: * Ensure the printer is plugged in and the power switch is turned on. * Verify that the toner cartridge and drum unit are installed correctly. * Check the interface cable connection. * Make sure the correct printer driver has been installed and chosen. * Check to see if the LCD is showing an error message. * Check the machine is online.
Why Brother MFC-7340 does not load paper and shows 'No Paper' or 'Paper Jam'?
If your Brother All in One Printer displays 'No Paper' or a 'Paper Jam' message, here's what you can do: * If there is no paper, load a new stack of paper into the paper tray. * If there is paper in the paper tray, make sure it is straight. * If the paper is curled, you should straighten it; sometimes it is helpful to remove the paper, turn the stack over, and put it back into the paper tray. * Reduce the amount of paper in the paper tray, and then try again.
How to remove vertical black line in copies from Brother All in One Printer?
Black vertical lines on copies are typically caused by dirt or correction fluid on the glass strip. Clean the scanner glass. The corona wire for printing may also be dirty, so clean the corona wire as well.
How to fix 'No detection of internal temperature thermistor' on Brother All in One Printer?
If your Brother All in One Printer displays 'No detection of internal temperature thermistor', check the harness connection of the internal temperature thermistor and reconnect it.
What to do if Brother All in One Printer says 'No paper'?
If your Brother All in One Printer displays 'No paper', reload paper into the tray and then press the start button to resume printing.
What to do if my Brother MFC-7340 does not answer when called?
If your Brother All in One Printer isn't answering when called, make sure the machine is in the correct receive mode for your setup, check for a dial tone, and if possible, call your machine to hear it answer. Also, check the telephone line cord connection.
How to fix 'Toner Low' on Brother MFC-7340?
If your Brother All in One Printer displays 'Toner Low', prepare a new toner cartridge. If the toner is empty, replace it.
What to do if there is a paper jam inside Brother MFC-7340 All in One Printer?
If you encounter a paper jam inside your Brother All in One Printer, open the front cover, completely pull out the drum unit, and then remove the jammed paper.
| Duplex printing | Yes |
|---|---|
| Print technology | Laser |
| Maximum resolution | 2400 x 600 DPI |
| Print speed (black, normal quality, A4/US Letter) | 24 ppm |
| Grayscale levels | 256 |
| Faxing | Mono faxing |
| Fax memory | 400 pages |
| Total input capacity | 250 sheets |
| Total output capacity | 100 sheets |
| Auto document feeder (ADF) input capacity | 35 sheets |
| Internal memory | 16 MB |
| Card reader integrated | - |
| Sound pressure level (printing) | 53 dB |
| Dimensions (WxDxH) | 428 x 396 x 304 mm |
| All-in-one functions | Fax, Scan |
| Color all-in-one functions | scan, n |
| Compatible operating systems | Windows Mac OS |
| Operating temperature (T-T) | 10 - 32.5 °C |
| Operating relative humidity (H-H) | 20 - 80 % |
| Copy speed (black, normal quality, A4) | 21 cpm |
| Power consumption (PowerSave) | 10 W |
| Power consumption (average operating) | 460 W |
| Maximum duty cycle | 10000 pages per month |
| Paper tray media types | Bond paper, Envelopes, Labels, Plain paper, Transparencies |
| Non-ISO print media sizes | Executive |
| ISO A-series sizes (A0...A9) | A4, A5 |
| Maximum ISO A-series paper size | A4 |
| Market positioning | Home & office |
Provides a detailed explanation of the machine's control panel functions and buttons.
Instructions on how to access and read the user guides available on the CD-ROM.
Step-by-step guide for loading paper into the standard paper tray.
Details on the types of paper and print media suitable for use with the machine.
Instructions for loading documents into the automatic document feeder (ADF) or scanner glass.
Configuration options for paper type and size to optimize print quality.
Adjusting the ring, beeper, and speaker volumes for machine notifications.
Prevents unauthorized access to the machine, restricting certain functions.
Restricts access to machine functions for public or individual users.
Password protection for machine settings to prevent accidental changes.
Basic steps and modes for sending faxes using the machine.
Instructions for sending documents from the automatic document feeder.
Adjusts fax settings to accommodate noise and static on overseas telephone lines.
Explanation of different modes for receiving incoming calls automatically.
Automatically responds to CNG tones if a fax call is interrupted.
How the machine stores incoming faxes when paper is low or out.
Information on features like Voice Mail and their compatibility with the machine.
Enables the Distinctive Ring feature to dedicate a number for receiving faxes.
Instructions for connecting an external Telephone Answering Device (TAD).
Methods for dialling telephone and fax numbers.
Storing and using one-touch keys for quick dialling.
Storing and managing speed dial numbers for efficient dialling.
Automatically forwards received faxes to another machine.
Receives faxes directly to your PC for viewing and storage.
Accessing and retrieving stored fax messages remotely.
Allows other machines to receive faxes from yours, they pay for the call.
Restricts access to polled documents using a secure code.
Sets up the machine to wait for another machine to retrieve a document.
Provides proof of fax transmission success or failure.
Prints an activity report of incoming and outgoing faxes.
Instructions on how to manually print various available reports.
Basic steps for entering copy mode and making copies.
Adjusting settings like Auto, Text, or Photo for optimal copy output.
Arranging multiple copies in sequential order.
Guide to navigating and reading the HTML user guides.
Instructions for accessing documentation on Windows operating systems.
Instructions for accessing documentation on Macintosh operating systems.
Guidelines for selecting a safe and suitable environment for the machine.
Essential safety instructions to reduce risks of fire, shock, or injury.
Laser safety information and specifications for the machine's laser diode.
Information on documents that should not be reproduced due to legal restrictions.
General guidance and chart for resolving common machine problems.
Explanation of error messages and required maintenance actions.
Step-by-step instructions for clearing document jams from the ADF.
Procedures for clearing paper jams from various locations in the machine.
Procedures for cleaning and maintaining the machine's components.
Instructions for replacing consumables like toner cartridges and drum units.
Guide to using the machine's LCD for programming and setup.
Reference table listing menu selections, options, and descriptions.
Steps to navigate and access different menu options on the machine.
Technical specifications including printer type, memory, power, and dimensions.
Details on paper types, sizes, weights, and capacities for input and output.
Technical specifications related to fax functionality, compatibility, and speed.
Specifications for copy functions, including color, size, resolution, and speed.
Minimum system requirements for PC software functions.
Network specifications for wired LAN connections.
Details on wireless network authentication and encryption methods.
Definition of the automatic document feeder for scanning documents.
Definition of forwarding received faxes to another number.
Definition of one-touch keys for storing numbers for easy dialling.
Definition of storing numbers for quick dialling using a three-digit code.
Definition of the transmission verification report.











