SKU:

MFC-9840

Printer Brand:

Brother

OEM Number:

TN115BK, TN115C, TN115M, TN115Y

Ink Color:

Black, Cyan, Magenta, Yellow

Page Yield:

Black:5,000, Color:4,000

Printer Type:

Laser Cartridge

Condition:

New Compatible

Frequently Asked Questions

My MFC-9840 is the hub of a busy home office — how long will this black realistically last me?

Home offices print in bursts: quiet weeks, then a project that eats a thousand pages. Rated at 5,000 pages for $44.92 (about 0.90¢ a page), this TN115BK absorbs those bursts without running dry mid-project, and in quieter stretches it simply waits — toner does not spoil between jobs the way ink can.

Which printers is it made for?

The cartridge fits the TN115 platform: DCP-9040CN, DCP-9045CDN, HL-4040CDN, HL-4040CN, HL-4070CDW, MFC-9440CN and MFC-9450CDN

I scan and copy more than I print — does copying use this cartridge the same way?

Yes. Every copy the MFC-9840 makes is a printed page, drawn from the same supplies: black for documents, the TN115C, M and Y cartridges (4,000 pages each) for color copies. Scanning to file, by contrast, uses no toner at all.

Is there a separate drum I need to budget for?

No separate drum listing exists for this platform in our store, because the drum unit is part of the printer itself rather than a cartridge you swap with toner. This page is the black toner cartridge only — when it empties, it is the only black supply you replace.

TN115BK or the standard TN110BK for a home office?

The TN110BK yields 2,500 pages. Occasional printers can live with that, but a busy home office hits the limit at the worst times — usually mid-deadline. The TN115BK doubles the runway to 5,000 pages at a lower per-page cost. When colors run low too, the TN115 four-color set ($127.02) renews all four together.

What cover do I have if it misbehaves?

A one-year warranty and one-year free returns, detailed on the shipping and returns page. It ships from IL, PA, GA or CA, with support available 9 AM–5 PM CST.

How should a spare TN115BK be stored in a home office?

Sealed in its packaging, lying flat in a drawer or cupboard away from direct sunlight and radiators. Toner is a dry powder, so unlike ink it does not dry out or clog while it waits — a spare bought alongside the installed TN115BK will still deliver its full 5,000 pages whenever the burst project finally arrives that finishes the current cartridge.

Pages from the MFC-9840 have gone light overall — how do I tell if it is just low toner?

Uniform fading across the whole page is the classic low-toner signature on this platform. Take the TN115BK out and rock it gently side to side, then print a test page: if the darkness returns, the cartridge simply needs its remaining powder redistributed and you have some runway left. Marks that repeat down the page or sit in one fixed band, by contrast, survive a cartridge change and belong to the machine side of the diagnosis.

What exactly should I read off the old cartridge before reordering?

The full code printed on its label: TN115BK. The letters matter as much as the numbers — the TN115C, TN115M and TN115Y units are this machine's color slots, and the TN110BK is a standard-yield black that fits but runs 2,500 pages instead of 5,000. Reading the code off the cartridge itself, rather than ordering from memory, is the simplest way to guarantee the high-yield black is what turns up.

Is keeping one spare really enough for a machine that works in bursts?

For most home offices, yes. The pattern that works is: one TN115BK in the MFC-9840, one sealed spare on the shelf, and a new order placed the day the spare goes in. Because burst projects announce themselves — a deadline, a tax season, a big filing — the spare covers the surge while its replacement is in transit, and the machine that anchors your office never becomes the reason work stops.

About This TN115BK for the MFC-9840

The MFC-9840 was built as the no-compromises home-office machine, and its supply strategy should be equally uncompromising: the biggest black cartridge the platform offers. This TN115BK's 5,000 pages at roughly 0.90¢ each mean the hub of your office is never the thing that stops work. Companion colors live on the Brother supplies page.