The drum unit, and the running cost nobody quotes what the counter measures, and what to do when it runs out
Toner is the powder. The drum is the green cylinder the powder sticks to, and it wears out on its own schedule, somewhere between two and eight toner cartridges later depending on which toner you buy. On some printers you buy it separately and on others it is welded into the cartridge you already buy, which is why two lasers with identical toner prices can cost very different amounts to run.
Not every laser has a drum you can buy
Of the 79 laser printers in our catalogue, 45 take a drum unit as a separate part and 34 do not. The split falls almost entirely along brand lines. 41 of the separate-drum machines are Brother and 4 are HP, while every one of the 34 machines with no drum SKU is an HP whose imaging drum is built into the toner cartridge and thrown away with it.
Both designs are defensible. An all-in-one cartridge means one part number and a fresh drum every time, at the cost of discarding a component with plenty of life left. A separate drum means a second thing to buy and a second counter to understand, and a lower cost per page once you get past the first year. The design also decides what a print defect means: on an all-in-one machine a scratched drum is fixed by the next toner cartridge, and on a separate-drum machine it is a distinct purchase that a new toner will not touch.
Check which you have before you buy anything. If your model's supply list on this site shows a DR number alongside the TN numbers, or a CF219A or CF232A alongside the toner, the drum is separate. If it lists only toner, it is not.
The counter measures rotations, not pages
The machine has no way to inspect the drum surface, so it counts how many times the drum turns and converts that to a page figure. Brother says as much in its own replacement instructions: it decided to use the number of rotations of the drum as a reasonable determinant of drum life, and when the drum reaches the factory established rotation limit corresponding to the rated page yield, the machine advises you to replace it.
A drum turns a fixed extra amount at the start and end of every job, whatever the job contains. So a one page job burns proportionally more drum life than a page inside a twenty page job, and Brother publishes both numbers. Its store lists the DR-820 at approximately 30,000 pages based on one page per job and 50,000 pages based on three pages per job, and the DR-431CL carries the same pair of figures. That is one drum at one price reaching 67 percent more paper because the work arrived in bigger batches.
At Brother's own 159.29 dollars that puts the DR-820 at 0.53c a page on the one page per job basis against 0.32c on the three page basis, with nothing about the printer changed. If you routinely print single sheets from a browser, the rated yield is the number that applies to you, and batching what you can is the one free way to move it.
The rated figure carries the usual caveats too. Brother states that many factors determine actual drum life, including temperature, humidity, paper type and toner used, and that it cannot guarantee a minimum number of pages. Our explainer on what a page yield measures covers why the toner number is a lab figure as well.
Read the message before you buy a part
Brother uses several drum messages and they do not all mean the same thing. One of them asks for nothing but a cleaning pass and is regularly mistaken for the others.
| Message | What it means | What to do |
|---|---|---|
| Drum End Soon, or Drums End Soon | The rotation count is approaching the limit | Order a drum. Brother says you can keep printing and change it when quality drops or the replace message arrives |
| Drum End Soon (X) | One colour drum only, on a machine with four. Brother notes this does not appear during a normal drum kit lifespan and points to a unit replaced earlier on its own | Replace the named colour |
| Replace Drum, or Replace Drums | The count has hit the factory limit | Fit a new drum and reset the counter |
| Drum Error, scrolling Slide the Green tab on Drum Unit | The corona wire needs cleaning | Slide the green tab left and right a few times and return it to the home position. No new part |
| Drum Error, scrolling Replace the Drum Unit | The drum itself | Replace it |
The green tab case is worth knowing because it costs nothing and takes ten seconds. Brother's own guidance also warns to return the tab to the home position with its arrow lined up against the arrow on the drum unit, since leaving it off centre puts a vertical stripe down every page.
HP handles it differently on the four machines in our catalogue with a separate imaging drum. The supply is reported through the same low and very low warnings as toner, and the user guide for the LaserJet Pro M118 to M203 range advises having a replacement available to install when print quality is no longer acceptable rather than at the warning itself. The same guide exposes a Very Low Setting (Imaging Drum) in the embedded web server with Continue, Stop and Prompt options, so you decide whether a very low drum halts the machine or just nags. The default lets you keep printing.
What the drum actually adds to a page
Cost per page tables almost always quote toner alone, which flatters every separate-drum machine on the market. The sum below covers the 45 lasers we track with both parts priced, using each machine's cheapest black toner and the drum that fits it. Every figure is manufacturer list price divided by rated yield.
| Printer | Drum | Drum per page | Cheapest black toner | Toner per page | Drum share |
|---|---|---|---|---|---|
| Brother HL-L2350DW | DR-730, 12,000 pages | 1.08c | TN-760, 3,000 pages | 2.83c | 28 percent |
| Brother HL-L2340DW | DR-630, 12,000 pages | 0.94c | TN-660, 2,600 pages | 2.23c | 30 percent |
| Brother HL-L3210CW | DR-223CL, 18,000 pages | 0.89c | TN-227BK, 3,000 pages | 2.60c | 26 percent |
| Brother HL-L8360CDW | DR-431CL, 30,000 pages | 0.61c | TN-436BK, 6,500 pages | 1.77c | 26 percent |
| Brother HL-L6200DW | DR-820, 30,000 pages | 0.53c | TN-880, 12,000 pages | 1.33c | 28 percent |
| HP LaserJet Pro M102w | CF219A, 12,000 pages | 0.50c | CF217A, 1,600 pages | 4.38c | 10 percent |
| HP LaserJet Pro M203dw | CF232A, 23,000 pages | 0.30c | CF230X, 3,500 pages | 3.14c | 9 percent |
The pattern holds across the whole set. On all 41 Brother machines the drum accounts for 25 to 30 percent of the cost of a black page. Across the 4 HP machines it is 9 to 10 percent. HP gets there by pairing a cheap, long-lived drum with expensive toner, and Brother by the reverse. The drums themselves run from 0.30c to 1.08c a page.
Read in cartridges rather than cents, a drum covers between 2.5 and 7.5 toner cycles depending on the pairing, with a median of 4.6. The narrow end of that range is the high-volume mono machines. Put the TN-880 in an HL-L6200DW and its 12,000 page toner uses 40 percent of the drum's rated life, so the drum runs out partway through the third one. At the other end, the CF219A in an M102w outlives 7.5 of the small CF217A cartridges, so a light user can own one for years without ever meeting the drum.
A separate drum is not a worse design for any of this. It does mean the advertised running cost of one is incomplete, so when you compare two lasers, add the drum line to both or to neither. Our cost per page ranking works from toner, so treat the figures above as the surcharge to apply to a Brother laser.
On a colour laser the drum is not the last part
Colour machines carry two more long-life consumables that running cost comparisons routinely leave out, and they are user replaceable rather than service parts. The belt unit carries the four colour images before they meet the paper, and the waste toner box catches what does not transfer. Both are ordinary purchases with part numbers.
Take the HL-L3210CW family. Brother's store lists the BU223CL belt unit at 160.29 dollars with a yield up to 50,000 pages and the WT223CL waste toner box at 37.29 dollars over the same 50,000. That is 0.32c and 0.075c a page. Add the DR-223CL drum at 0.89c and the parts that are not toner come to 1.29c a page, against 2.60c for the TN-227BK black toner itself. A black page on that machine costs 3.89c once everything in the imaging path is counted, and 33 percent of that never appears in a toner comparison.
The belt and waste box are rated well beyond the drum, so on a home machine they usually arrive once and the drum arrives twice. And on a four drum colour machine Brother points out that the drums rotate together during every stage of operation even when you are printing in one colour, which is why the kit is replaced as a set and why colour drum life does not stretch just because you print mono.
Drum or toner? The page usually tells you
Work out which part is causing the symptom before you spend anything, because the two failures look different on paper.
- Fading that clears when you rock the cartridge is toner settling, not drum wear. Take the cartridge out, rock it gently end to end and refit it. If a few hundred more pages come out clean, you bought time on the toner.
- A grey haze or speckling across the whole sheet that a new toner does not fix points at the drum surface or the corona wire. Try the green tab clean first.
- A mark that lands in the same place on every page comes from something that rotates, and the gap between repeats identifies the part. Our guide to reading a bad print has the measuring method.
- A single sharp vertical stripe on a Brother is often the green tab left off centre after a clean rather than anything worn.
- Blank pages are usually neither. The orange shipping tab still in a new cartridge and a driver pointed at the wrong device account for most of them, which the blank pages guide covers.
If the drum is genuinely worn, the visible damage is on the green cylinder, and scratches and flat spots both print. Look at it under good light with the cartridge separated, and keep it out of daylight while you do, since Brother notes an unpacked drum left in direct sunlight or long exposure to artificial light can be damaged.
Fitting one, and the counter reset
On a Brother the toner and drum come out as one assembly. A green lever on the side releases the toner cartridge from the old drum so it can go straight into the new one, so you are not throwing away half full toner when the drum expires. The reset is a separate step and the machine will keep reporting the old count until you do it.
The reset differs by model even inside one generation. On the HL-L3290CDW and DCP-L3551CDW Brother has you hold OK, select Drum, choose the colour and confirm. On the MFC-L3710CW, MFC-L3750CDW and MFC-L3770CDW it is a five second press, then Drum on the touchscreen, then the colour, then Yes. Check the procedure for your own model rather than copying one from a similar machine. Our Brother counter reset guide covers the toner side of the same menus.
Whatever the sequence on your model, do not use it to clear a warning. Brother is explicit that you should not reset the drum counter unless you are replacing the drum unit, because a machine whose counter no longer matches the part cannot calculate remaining life. Resetting to silence a warning works exactly once and leaves you with no warning at all next time.
Third party drums exist and are usually a third of the price. Brother's position is that printing with a non-Brother drum may reduce print quality and the life of the machine, and that warranty coverage does not apply to problems caused by one. There is no lockout chip in the way there is on some ink printers, so the choice is yours to make on price and risk rather than one the printer makes for you. OEM versus compatible versus remanufactured covers how that trade off usually plays out.
Common questions
What is the difference between a drum unit and a toner cartridge?
Toner is the powder that forms the image. The drum is the light-sensitive cylinder that picks the powder up in the right pattern and rolls it onto the paper. Toner is consumed page by page and the drum wears mechanically, so they run out on different schedules. On the 45 lasers in our catalogue that take a separate drum, one drum covers between 2.5 and 7.5 toner cartridges depending on the pairing.
Does my printer have a separate drum unit?
It depends on the model rather than the brand alone. Of the 79 lasers we track, 45 take a drum as a separate part and 34 build it into the toner cartridge. 41 of the separate-drum machines are Brother, where the drum carries a DR number alongside the TN toner numbers, and 4 are HP, using the CF219A or CF232A imaging drum. Every other HP laser we list puts the drum inside the cartridge. Your model's page on this site lists whichever parts fit it.
Can I keep printing after the Replace Drum message?
Yes, and Brother says so directly: the product will continue to function, though print quality may not be optimal. The message reports a rotation count reaching a factory set limit, not a measurement of the drum, so a drum in good condition can keep producing acceptable pages past it. Replace it when the pages stop being good enough, and order it when the earlier Drum End Soon warning appears so you are not stuck waiting.
Why does my drum say it needs replacing when the printer has printed far fewer pages?
Because the counter measures drum rotations rather than sheets. The drum turns a fixed extra amount at the start and end of every job, so short jobs use disproportionately more drum life. Brother publishes both figures for some units. The DR-820 is rated at 30,000 pages based on one page per job and 50,000 based on three pages per job, so the same drum reaches 67 percent more pages when the work arrives in threes.
How much does the drum add to my cost per page?
More than most comparisons admit. Using manufacturer list prices and rated yields across our catalogue, the drum accounts for 25 to 30 percent of the cost of a black page on the Brother machines and 9 to 10 percent on the HP ones, with the drum itself costing between 0.30c and 1.08c a page. HP pairs a long lived cheap drum with expensive toner and Brother does the opposite, so the totals land closer together than the toner prices suggest.
Should I reset the drum counter without changing the drum?
No. Brother's instructions say not to reset the drum counter unless you are replacing the drum unit, because after a false reset the machine cannot correctly calculate remaining drum life. You silence the message once and then have no warning before the drum starts putting marks on your pages. If the message is early and the print quality is fine, simply keep printing and order the part.
What does Drum Error mean on a Brother printer?
It has two cases and only one of them costs money. If the scrolling text asks you to slide the green tab on the drum unit, the corona wire needs cleaning: slide the tab left and right several times and leave it in the home position with its arrow aligned. If the scrolling text asks you to replace the drum unit, it means the drum. Leaving the tab off centre after a clean prints a vertical stripe, so a machine that starts striping right after a corona clean usually needs the tab nudging rather than a new part.
Do colour lasers need anything besides drums and toner?
Yes, a belt unit and a waste toner box, both user replaceable and both routinely left out of running cost comparisons. On the Brother HL-L3210CW family Brother lists the BU223CL belt at 160.29 dollars and the WT223CL waste box at 37.29, each rated up to 50,000 pages, which works out at 0.32c and 0.075c a page. With the drum included, the non-toner parts come to 1.29c a page on that machine.
Keep reading
- What a page yield actually measures why the toner number is a lab figure, and the drum number is not even that.
- Resetting a Brother toner counter the same menus, for the part that runs out first.
- Which printers are cheapest to run toner cost per page, ranked, before you add the drum line.
- Reading a bad print measuring a repeating mark to name the part that made it.
- Ink or toner? where the two consumable models diverge in the first place.
- What to do with empty cartridges the spent drum goes back under the same free label.
- HP LaserJet toner compatibility chart which HP lasers take a separate drum and what it adds per page.
- Setup cartridges and what the first refill costs the other consumable a new laser owner has not budgeted for.
- Your cartridge is being discontinued: what to do about it the second consumable to price before stocking up on toner.
Sources
- Brother, Replace the Drum Unit, on rotations as the determinant of drum life, the factory established rotation limit, continuing to print after the message, sunlight damage, the model by model counter reset, and the warning against resetting without replacing. brother.com
- Brother, Drums End Soon and Drum End Soon (X), on the difference between the kit warning and a single colour warning, and on continuing to print until quality drops. brother.com
- Brother user guide, Drum units, on the Drum Error message having two cases, the green tab and corona wire clean, the vertical stripe from a misaligned tab, and the four drums rotating in unison even when printing one colour. brother.com
- Brother USA store, DR820 drum unit, for the price and for the dual rating of approximately 30,000 pages based on one page per job and 50,000 pages based on three pages per job. brother-usa.com
- Brother USA store, DR431CL drum unit, carrying the same one page and three pages per job pair of figures. brother-usa.com
- Brother USA store, BU223CL belt unit and WT223CL waste toner box, for the prices and the yields used in the colour laser sum. brother-usa.com
- HP, LaserJet Pro M118-M119, M203-M205 and LaserJet Ultra M206 user guide, on the imaging drum very low indication, the advice to install a replacement when print quality is no longer acceptable, and the Very Low Setting (Imaging Drum) Continue, Stop and Prompt options in the embedded web server. hp.com
- HP support, Replace the imaging drum on an HP LaserJet Pro MFP M130-M132, M227 printer, on replacing when prompted, when damaged, or when print quality is unacceptable. hp.com
Last updated . This guide is general information, not a repair warranty. Printer menus and HP's model lists change, so confirm the exact steps for your model on the manufacturer's support site before you make changes.