how to install a toner cartridge step by step without damaging it in HP, Brother and Canon printers

Artículo · Printing Blog | Startoner

How to install a toner step by step without damaging it

July 6, 2026 Actualizado 18 julio 2026

Changing a toner seems trivial until the printer throws up a "toner not recognised" or starts printing with streaks. Most failures when installing a new cartridge don't come from the cartridge: they come from three avoidable mistakes. One of them, firmware blocking, cost HP a fine of 10 million euros from the Italian competition authority in December 2020 (Actionable Intelligence/AGCM, 2020). In this guide we explain how to install the toner in your HP, Brother, Canon or Samsung laser printer without damaging it, and what to do when the machine refuses to recognise it.

Key points
- Rock the cartridge 5-6 times and remove the orange seal completely before inserting it.
- Never touch the green surface of the drum or the electrodes.
- The "non-genuine" error usually comes from the firmware, not the toner: in 2020 the AGCM fined HP €10 million for blocking third-party cartridges (AGCM, 2020).
- A compatible toner usually costs between 30% and 70% less than the original.

Step 1: How do you prepare the toner before installing it?

Before you touch anything, prepare the cartridge. Brother recommends in its official support that you unbox the toner just before installing it, because the light in the room or the sun can damage the drum (Brother Support, 2026). Take the cartridge out of the bag, hold it by the ends and don't let minutes go by with it exposed.

Rock the cartridge gently from side to side, between five and six times, holding it by both ends. This action spreads the toner powder evenly inside the cartridge, which avoids light patches or streaks on the first sheets (HP LaserJet Support, HP reference; standard practice).

And what if your toner is a first installation? Same thing. Shake it too. It's the habit that saves us the most faint-print problems.

Brother states in its official support documentation that the drum should be unboxed just before installing it, since exposure to sunlight or even to a room's lighting can damage its photosensitive surface and permanently ruin print quality (Brother Support, 2026).

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Step 2: How do you remove the sealing strip correctly?

This is the step where most people go wrong. The sealing strip is a strip of plastic, usually with an orange tab, that keeps the toner sealed inside the cartridge during transport. HP states that you must pull that tab to remove the seal completely before inserting the cartridge; if it is left half in, the printer gives an error or doesn't print (HP LaserJet Support, 2016).

Hold the cartridge firmly and pull the tab in one continuous motion, in a straight line, until the whole strip comes out. Don't yank it out in short tugs: it can snap and leave half the seal inside. If you feel resistance, stop and check that you're pulling at the right angle.

At Star Toner we test and print with our own compatible toners before we sell them, and the number one fault we see reproduced by customers is not a faulty cartridge: it's the seal half removed. The second most common cause is having touched the drum. Both are resolved in under a minute by following these steps.

my printer prints with streaks

Step 3: How do you place the cartridge in the printer?

With the seal out, you can now insert the cartridge. Open the front cover of the printer, line the toner up with the internal guides and slide it in gently until it clicks into place. Most HP, Brother, Canon and Samsung lasers use the same principle of side guides, so if it doesn't go in first time, don't force it: check the orientation.

Push until you hear the click that confirms it's in position. Close the cover fully. If the cover won't close, it's almost always because the cartridge hasn't fully engaged. Switch the printer on and print a test page to check that it distributes the toner evenly.

Does the first sheet come out a little faint? That's normal with freshly installed cartridges. It usually corrects itself after two or three pages.

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The 3 mistakes that damage a new toner

Three specific actions ruin a cartridge before it prints its first sheet, and they all appear in the manufacturers' safety documentation. Brother warns against touching the surface of the drum or the electrodes, and against protecting the drum from light (Brother Support, 2026). These are the three that do the most damage.

Mistake 1: Touching the surface of the drum

Never touch the green or shaded part of the drum. It is the photosensitive area that transfers the image to the paper, and the grease from your fingers leaves marks that appear on every sheet. If you touch it by accident, clean it with a dry, lint-free cloth, very gently. No water and no products.

Mistake 2: Touching the electrodes

Don't touch the metal electrodes on the cartridge either. The static electricity from your body can damage the printer, as Brother indicates in its official support (Brother Support, 2026). Always hold the cartridge by the plastic handles or ends.

Mistake 3: Exposing the drum to light

Unbox the drum just before installing it. Leaving it out of its bag under the room light, or worse, in the sun, degrades the photosensitive surface. If you have to leave it for a moment, cover it with a cloth or put it back in its protective bag.

Why doesn't the printer recognise the toner?

When "toner not recognised" or "non-genuine cartridge" appears, the problem is usually in the firmware, not the toner. Dynamic Security is the technology HP introduced in 2016 to detect and block cartridges that don't carry an HP chip (HP, 2024). Firmware updates can end up blocking compatible cartridges that worked fine before.

This is not a theory. In December 2020, the Italian competition authority (AGCM) fined HP 10 million euros for using precisely this firmware to block third-party cartridges (Actionable Intelligence/AGCM, 2020). If your HP suddenly rejects a cartridge, check whether there was a recent update.

The "non-genuine cartridge" error on HP printers does not mean the toner is faulty. It is down to Dynamic Security, a firmware system active since 2016 that blocks cartridges without an HP chip. In December 2020, the Italian AGCM sanctioned HP with 10 million euros for this practice (AGCM, 2020).

When a customer writes to us with a "non-genuine cartridge", the first thing we ask is whether the printer updated recently. In our experience, that's the pattern: the toner was working, a firmware update arrived and it stopped recognising it. The cartridge is fine; it's the software that changed its mind.

my printer won't recognise the compatible toner

how HP firmware blocks cartridges

Do you lose the warranty by using a compatible toner?

No, using a compatible cartridge does not automatically void your printer's warranty. As a principle in the EU, it is the manufacturer who must prove that the compatible cartridge caused the fault, not the other way round. This criterion was reinforced by the 2022 Euroconsumers settlement, of around 1.3 million euros, which covered Spain, Portugal, Italy and Belgium (Born's Tech/Euroconsumers, 2022).

In practice, this means you can use compatible toner with peace of mind. The saving is no small thing either: a compatible cartridge normally costs between 30% and 70% less than the original for the same page yield (Toner Buzz, 2025).

Using a compatible toner does not, in itself, void the printer's warranty in the EU: the burden of proving that the cartridge caused the fault falls on the manufacturer. This principle was reinforced by the 2022 Euroconsumers settlement, of around 1.3 million euros, which covered Spain, Portugal, Italy and Belgium (Euroconsumers, 2022).

legal warranty of compatible cartridges in Spain

original vs compatible toner, we print it side by side

What do you do if toner powder spills?

If you drop toner, don't reach for the vacuum cleaner. Toner powder is a very fine plastic, around 5 to 10 microns, that passes through the filter of a domestic vacuum cleaner and can cause a static or fire risk (RK Black, 2023). Always clean it up with cold water, never hot.

Why cold water? Because heat melts that plastic and fixes it to the surface or the fabric, and then it won't come out. Pick up the bulk with a cold, damp cloth, and if it stains your clothes, wash them in cold water. Hot water turns a temporary stain into a permanent one.

To fit a replacement cartridge without any nasty surprises, take a look at our compatible toner collection with models for HP, Brother, Canon and Samsung.

Frequently asked questions

Why does my HP say "non-genuine cartridge"?

Almost always because of Dynamic Security, the firmware HP has used since 2016 to block cartridges without its chip. An update can reject a cartridge that worked fine before. It does not indicate a faulty toner: in 2020 the Italian AGCM fined HP 10 million euros for this practice (AGCM, 2020).

Do I lose the warranty by using compatible toner?

Not automatically. As a principle in the EU, the manufacturer must prove that the compatible cartridge caused the fault. The 2022 Euroconsumers settlement, of around 1.3 million euros, reinforced this criterion in Spain, Portugal, Italy and Belgium (Euroconsumers, 2022).

Do you need to shake the toner before installing it?

Yes. Rock the cartridge between five and six times, holding it by the ends, to spread the powder evenly. This action, recommended by HP, avoids streaks and light patches on the first sheets (HP LaserJet Support, 2016). Do it with new first-installation cartridges too.

What do I do if I touch the drum by accident?

Don't panic. Clean it carefully using a dry, lint-free cloth, with no water and no products. Brother warns against touching the green surface of the drum because the grease leaves marks on every sheet (Brother Support, 2026). If the marks persist, the drum may have been damaged.

How much do I save with a compatible toner?

It depends on the model, but a compatible normally costs between 30% and 70% less than the original for the same page yield (Toner Buzz, 2025). The saving is greater on high-volume printers, where spending on consumables exceeds that of the machine itself.

Conclusion

Installing a toner properly comes down to three things: shake it, remove the whole seal and don't touch the drum or the electrodes. If you do that, most quality problems disappear before they arise. And if your printer throws up a "non-genuine cartridge", remember that it's almost always the firmware talking, not a defect in the toner: there's a reason the AGCM fined HP 10 million euros in 2020. Using compatible is legal, it's your right in the EU and it saves you money. The next time you change a cartridge, you'll know exactly what to do and what to avoid.