The Brother TN-3430 and TN-3480 (known as TN-820/TN-850 in North America) are high-capacity toner cartridges designed for heavy-duty laser printers like the Brother HL-L5000 and MFC-L6800 series. To maintain professional print quality while reducing costs, a proper refill and reset procedure are essential.
In this guide, we will demonstrate the correct way to refill these units. However, for critical business documents, we recommend using new high-yield cartridges to ensure consistent density and avoid mechanical wear.
Refill and Reset Instructions
- Opening the Cartridge: First, remove the side cover to access the refill plug and the reset gear mechanism. Our video highlights the exact steps at [01:24].
- Cleaning the Developer Roller: Subsequently, it is vital to clean the metal developer roller. A dirty roller will cause faint prints or vertical white lines.
- Refilling the Toner: Open the plug and pour in the specialized Brother monochrome toner powder. Consequently, ensure the hopper is not overfilled to allow the internal agitation to work correctly.
- Resetting the Gear: Additionally, you must manually reset the flag gear. Unlike some other brands, Brother uses a mechanical gear position to signal a “New Toner” to the printer.
- Professional Replacement: While refilling is efficient, replacing the unit with a factory-sealed TN-3480 or TN-850 is the most reliable way to prevent toner leaks and ensure a full 8,000-page yield.
Recommended Brother Replacement Units & Hardware
For the best performance, we suggest these high-quality replacement options:
- High-Yield Toner (USA): Brother Genuine TN-850 High Yield Black Toner – The top choice for North American L5000/L6000 series printers.
- High-Yield Toner (Europe): Brother Genuine TN-3480 Black Toner – Original reliability for European models.
- Drum Unit: Brother DR-3400 (DR-820) Drum Unit – Essential for crisp text. Replace this every 30,000–50,000 pages.
- Maintenance Essential: Anti-Static Toner Wipes – Perfect for cleaning the developer roller without leaving lint.
- Modern Printer Successor: Brother New Models – If your old printer is failing, this is the ultimate high-speed monochrome workhorse.
Expert Tip
If your printer still says “Replace Toner” after refilling, the reset gear was likely not set in the correct starting position. Furthermore, always make sure to wipe the corona wire on the drum unit (the green tab) to prevent background speckles on your prints.
Looking for more professional guides? Check our tutorials on Kyocera DK-1150 Maintenance or Lexmark MS317 Refill Steps.
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