Printer Faults - Noisy Printer

Print technologies differ greatly in the amount of noise they make, ranging from almost silent with thermal printers where the only moving part is the paper feed roller through to the shriek of a dot-matrix printer with it's lid open.

Laser printers are not very noisy in operation. Compared to the thump-thump of an inkjet and the shriek of dot-matrix machines they are generally quiet.   Larger printers do tend to have a couple of cooling fans and there will be the usual noises of pickup rollers, paper moving, cogs churning and clutches operating.

Modes and Noise

Laser printers have two or three main operating modes - sleep, idle, power-save, standby and printing for instance (the names differ by manufacturer). When the printer is doing nothing and has done nothing in the last few minutes it will generally go into a low power "sleep" state with just one supervisory processor running and a message on the control panel. Everything else is shut down and the printer should therefore be silent. There may be a background whistle or hum from the power-supply.

In stand-by mode most designs of printer are likely to be heating the fuser. Because there is a heat source running in the printer they need an air-flow to prevent any localised build-up so there will be the noise of a fan running. In a typical office with other computers and air conditioning this noise probably won't be noticeable and is unlikely to be obtrusive. In a small office or a domestic environment it could be an annoyance.

Canon and HP printers often have "Instant On" fusers. The fuser heats up very rapidly when needed. This is primarily intended to cut the stand-by power consumption but it does also mean that standby noise is reduced - if a fan has to run at all it is just for a few minutes after a print.

In normal operation there are a series of noises from a laser printer.

• there is the high pitched whine of the polygon mirror(s) spinning up
• the clunk of the paper feed rollers engaging
• a noise of paper moving- a hiss or "swoosh"
• a click as the registration station clutch engages
• various squeaks and groans from the print cartridge cogs and particularly the scraper blade.
• the trundling noise of a motor driving a cog chain.
• and finally the print emerges and the next page begins.

Spelled out like that makes things seem worse than they actually are. In practice people sit next to some laser printers and scarcely notice them working. (We don't recommend sitting next to printers but that's an issue with particle emissions not noise)

Manufacturers Figures

Printer manufacturers generally give some figures for noise. Ideally the declaration should accord with ISO 9296 and should give the sound power in Bels in a way that can be compared with other manufacturers figures. One problem is that most people have no idea what a noise measurement means in practice. Take this for a fairly common printer, the HP CLJ CP4025n for instance:

Acoustics Sound power emissions 15 Active: 6.8B(A): Ready 5.0B(A), Sound Pressure (bystander position) Idle: 35dB; Operating:54dB 15 Declared per ISO 9296 and 7729; values are subject to change. Configuration tested: HP Color LaserJet CP4025dn, printing at 35 ppm on A4 paper.

If you aren't a sound engineer that probably means next to nothing to you. That isn't the manufacturers fault because their only alternative is poetic simile like whisper quiet. At least the figures can be compared with others.

Sound power is figure that should be looked at because it should be more reliable. A quieter printer will have a lower figure.

Another problem is that it isn't necessarily the power of a noise but it's quality that causes irritation.

Noises and Faults

The worrying noises are those that suggest something vital failing in the printer.

Some faults have characteristic noises. Some printer faults self-diagnose because a noise happens (or an expected noise doesn't happen).

The most worrying noise is usually of the cog whining kind, sometimes followed by rumble of cogs degenerating. Truly terrific noise like a bad gearchange in a car after replacing a cartridge or fuser usually indicates it didn't seat correctly. Immediately turn the printer off. Check that the cartridge gear-chain is capable of turning - it isn't entirely unknown for a refurb not to be. Are the shipment locks out (they are usually bright orange). Check for damage to the cogs. Reseat the thing and try again.

Less dramatic noises from on a laser printer are notoriously difficult to diagnose, especially on site. If the printer doesn't show any fault there is no indication of what is wrong. The printer needs all the parts in and the lids closed before it will work at all. Once the printer is working several things happen at once and whilst there is a sequence to events all the parts of the printer are often turning at the same time. Spotting the specific part to blame means running with lid-switches foxed and the sides off. That potentially means exposure to the laser, the high voltages used for transfer and the mains voltage used by the fuser. Tracing noise issues is a job for an experienced technician and before getting involved we suggest trying the printer on a firm surface, like the floor. If the noise disappears in another place the problem is chassis distortion. It doesn't matter that it always worked there in the past.

Noises that Gradually Worsen

Notorious cases are:

LaserJet 4200 / 4300 problem with the swing-plate assembly.

The 4200 /4300 fusers were designed to be easy to change - they simply unclip. Several problems later emerged. The clips might sometimes be slack. There is also a problem with the drive cog on the swing plate assembly not running true which is fixed by a spacer. It's an annoying fault because the printer may have to be half dismantled to fix it - there are more details here . In this case the noise is a symptom of something going wrong. If the cog isn't replaced it will be damaged and will spoil those nearby.

LaserJet 2400

The 2400 (and sometimes its successors the P3005 / M3027 / M3035) can make an annoying bandsaw noise. The noise seems to be caused by the teeth on adjacent cogs brushing against one another. A common cure is to put a small spacer washer around the locating pin on the cog side. There are more details here . In this case the noise does indicate gear wear although it doesn't seem to do immediate harm except to the users ears.

LaserJet P3005

The P3005 is also known for a rumbling noise. Probably a fuser bushing has cracked.

The cases mentioned are HP designs but that is because these machines are particularly popular, rather than specially prone to noisiness.

If a noise worsens over time that does imply that something is wearing out or breaking down. A problem with noise is that it doesn't take much energy to make a sound. The LaserJet 2400 bandsaw noise is aggravating but its just the teeth on two nearby cogs rubbing slightly - the cogs themselves are not much damaged.

Last Thing Changed Is Wrong

Noises are particularly likely to be remarked on after a part has been changed - cartridges and fusers being the things most likely to be changed.

Dramatic gear-stripping noises usually imply something went badly wrong.   Experienced engineers tend to leave their finger on the power switch of a machine after making a big change just in case. (Experience may make you less liable to mistakes, it also makes you cautious).

Cartridge Noises

Cartridges aren't usually noisy. The average one-piece cartridge contains toner, possibly some stirrer paddles, developer, doctor-blade, pre-charge roller, drum, scraper blade and probably a waste toner receptacle. In other word its a set of rollers driven by cogs down the side. It isn't easy to turn the parts of a cartridge because the scraper blade in particular puts quite a lot of pressure on the drim, but it should be possible (watch out for blotches of toner on clothes) It is not unknown for a cartridge to not turn. Refurbs are often to blame, the cartridge has been badly reassembled. It isn't impossible with a brand new cartridge that has been stored badly, the scraper blade might stick to the drum for instance.

Fuser Noises

Changing a fuser does sometimes give a noise issue where there was non before. Fusers are usually dumb devices, there is very little in the fuser capable of making much noise without the whole mechanism actually falling to bits. Noises after a fuser has been changed are usually going to be:

• miss-seating the new part isn't clipped or screwed in correctly.
• worn drive-chain cogs revealed by the new drive cog on the fuser.
• chassis distortion again revealed by changing a part.

Things which can make noise on a fuser are:

Pressure roller issues. Many fusers have a metal pipe as the heated roller with a rubber roller pressed against it. The rubber roller is hard, but has some give in it. Some fusers (not all) have pressure release levers which disengage the pressure whilst the fuser is shipped and stocked. If the pressure release is not in the correct position the rubber roller distorts somewhat and will make a whump-whump noise when the fuser turns. The printer will probably work but the noise is distracting. The noise may well go away after a couple of days, as the rubber returns to shape. Fusers should be shipped with the locks correctly positioned. In fact some manufacturers will advise taking the fuser out and putting the locks in position if a printer is put into store.

Broken bearings are a possibility with refurbished fusers. Fuser bearings are not usually ball or roller bearings because they would jam on paper dust. The bearing is usually a collar of plastic at each end of the fuser roller, the plastic is a Teflon / fluon -type of material (Polytetrafluoroethylene) and is quite soft when new but brittle when older The noise varies but will typically be a grinding or screech.

Cog noise is also likely. Fuser cogs deal with quite a lot of load because the pressure roller does not run freely against the heater. Where cogs have been used together for a long time they tend to wear to match one another. Put a brand new fuser in place and the new fuser doesn't match the worn drive cog quite as well as the old one did giving rise to cog noise. One possibility would be to change the fuser drive cog as well, but that often isn't an easy option because it means dismantling a drive-chain - not an easy task. Do NOT oil fuser cogs; the best that can happen is that the oil will dry up. Most likely the hard plastic used by the cog will absorb the oil and split.

Some fusers are more complicated. The fuser in the HP CLJ 5500 has its own drive motor and power supply nearby.

Changing one part only to have it reveal a problem with another is a peril of all engineering tasks.

Chassis Distortion

Many cases of noise are due to the printer's position. Low cost office furniture is often made from chipboard and lacks the strength to properly support a heavy printer, especially a colour machine. The printers themselves usually but not invariably have a steel inner chassis, but it isn't built to be entirely self-supporting, it needs a firm, even surface to stand on.

Examine what the machine is standing on - is it a flat, even surface and fully capable of supporting the machine? Place a ruler edge-down near the printer, is the desk surface concave under it's weight? When the printer is making a noise put hand pressure on parts of the case near the noise and note how it changes. Try lifting the corners of the machine very slightly to see if that changes the noise substantially. Try sliding a beermat under each foot in turn. If it does (and particularly if it reduces it) then it rather implies that the machine's position is distorting the frame a bit.

If the noise gets worse when you change the distribution of pressure in a printer chassis the implication is that there is a distortion. Perhaps something isn't screwed in quite tightly enough.

Try putting the printer on the floor (assuming it is even and doesn't have a carpet that would interfere with the ventilation.