Brother MFC-7840W Manual

The Brother MFC-7840W is a monochrome laser All-in-One printer featuring print, copy, scan, and fax capabilities with wireless connectivity. It supports USB and network printing, automatic document feeder (ADF), duplex printing, and offers high-speed performance for home or small office use. Below are key sections for setup, features, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation & Setup 3. Specifications 4. Control Panel & Functions 5. Loading Paper & Toner 6. Printing Documents 7. Copying & Scanning 8. Fax Operations 9. Wireless Setup 10. Maintenance & Care 11. Troubleshooting

Features at a Glance

Key components: Control panel with LCD display, Paper trays, Automatic Document Feeder (ADF), Toner cartridge compartment, USB port, Ethernet port, Wireless antenna.

Feature	Description
Print Speed	Up to 30 pages per minute (ppm)
Resolution	Up to 1200 x 1200 dpi
Paper Capacity	250-sheet input tray
Automatic Document Feeder	35-sheet capacity for copying/scanning
Connectivity	USB 2.0, Ethernet, Wireless 802.11b/g/n
Duplex Printing	Automatic two-sided printing
Fax Capability	Super G3 with 33.6 Kbps modem
Compatibility	Windows, macOS, Linux, mobile printing
Toner Yield	Approx. 3,000 pages (standard cartridge)
Display	2-line LCD with navigation buttons

Installation & Setup

Unpack and inspect contents. Place on stable, level surface near power outlet.

Install toner: Open front cover, remove packaging from cartridge, insert until clicks.
Load paper: Adjust paper guides in tray, load up to 250 sheets of plain paper.
Connect power: Plug power cord into printer and wall outlet, then power on.
Install drivers: Use included CD or download from Brother website for your OS.
Wireless setup: Use WPS or manual configuration via control panel menu.

WARNING! Do not touch the green drum surface of the toner cartridge. Keep printer away from heat and moisture.

Specifications

Type: Monochrome Laser All-in-One.
Functions: Print, Copy, Scan, Fax.
Print Speed: Up to 30 ppm.
First Print Out: Less than 10 seconds.
Memory: 64 MB standard.
Paper Sizes: Letter, Legal, Executive, A4, A5, B5, envelopes.
Scan Resolution: Up to 1200 x 1200 dpi (optical).
Fax Transmission: Approx. 3 seconds per page.
Power Consumption: Approx. 470W (printing), 65W (ready), 1.4W (sleep).
Dimensions: 16.1" W x 16.2" D x 15.6" H.
Weight: Approx. 30.9 lbs.

Control Panel & Functions

Access functions via buttons and 2-line LCD display.

Buttons: POWER, START (copy/scan), STOP/EXIT, Numeric keypad, FAX START, MENU, UP/DOWN arrows, OK, BACK.

Menu Options: Print Reports, Network Settings, Fax Settings, Copy Settings, Scan Settings, Device Settings, Maintenance. Use arrows to navigate, OK to select.

LCD Indicators: Shows status, error messages, page count, wireless signal strength.

Loading Paper & Toner

Paper: Pull out paper tray, adjust guides, fan paper, load print-side up. Toner: Open front cover, remove old cartridge, unpack new, shake horizontally, insert firmly.

Ensure printer is on and idle.
For paper: Do not exceed tray capacity; use supported paper types.
For toner: Avoid exposure to light; recycle used cartridges.

Tip: Use paper between 16-28 lb. bond for best results. Store toner in cool, dry place.

Printing Documents

Supports USB, network, and wireless printing from computers and mobile devices.

Install drivers and software from Brother website.
Select Brother MFC-7840W as default printer in OS settings.
Open document, select Print, adjust settings (copies, duplex, quality).
For mobile: Use Brother iPrint&Scan app or AirPrint (iOS).
Monitor status via control panel LCD.

WARNING! Do not open covers during printing. Allow printer to cool if heavy use.

Copying & Scanning

Copy: Place original in ADF or on glass, press START. Adjust copies, darkness, size via menu. Scan: Use ADF or flatbed; scan to email, network folder, or USB via control panel or software.

Fax Operations

Connect phone line to LINE port. Send: Load document, dial number, press FAX START. Receive: Set mode (Fax, Tel/Fax, Answering Machine). Program speed dials and fax settings via menu.

Wireless Setup

Use WPS: Press WPS button on router, then navigate to Network > WPS on printer menu. Manual: Select network name, enter password via keypad. Verify connection via network report.

CAUTION! Ensure wireless signal is strong; avoid interference from other devices.

Maintenance & Care

Unplug before cleaning. Exterior: Use dry, soft cloth. Interior: Remove paper dust with vacuum. Drum cleaning: Run Drum Cleaning from maintenance menu. Firmware updates: Check Brother website periodically.

CAUTION! Do not use alcohol or abrasive cleaners. Keep vents clear.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Printer not powering on	Power connection	Check power cord and outlet; ensure power switch is on.
Poor print quality	Toner/low cartridge	Replace toner cartridge; run Drum Cleaning; check paper type.
Paper jams	Paper misloaded/damaged	Open covers, remove jammed paper gently; reload paper correctly.
Wireless not connecting	Signal/settings	Check router; re-enter password; move printer closer to router.
Scanner not working	Driver/connection	Reinstall scanner driver; ensure USB/network connection is secure.
Fax transmission fails	Phone line/noise	Check line connection; use a different phone line; reduce line noise.

Reset: Menu > Device Settings > Reset Settings if needed.

Support: 1-877-267-8437; support.brother.com