Brother Laser Printer - paper indentations

[Grumps]

Hello Sorry, this is not a CV-19, BLM, or BREXIT question.

I have an HL3140CL colour laser printer which has been really good over the last few years. Sadly, today, it has started to produce small (about 5mm) indentations every 6.5cm (approx) 1/4 of the page width from the left edge. I know it must be dirt/debris on a roller, or that's what it seems like to me, but I don't know which is the likely candidate. I've removed as much as you can without using a screwdriver and found nothing suspicious yet. Any clues? I don't have a service manual. TIA.

[The Natural Philosopher]

Is this helpful?

[Harry Bloomfield, Esq.]

The answer is easy - Which roller in the printer has a circumference to exactly match the 6.5cm? 65/3.142 = 20.69mm

[Grumps]

Thanks. I'd not found that page yet. Sadly, I don't think that's where the problem lies. There's no problem with the printing as such, just the little indentations.

[Grumps]

There must be a roller hidden somewhere. I've not found one that size (yet).

[Theo]

Print blank pages, and turn off the printer halfway through. If you do this a number of times you'll catch the paper in different stages of the print path, and can see what's causing the problem.

Theo

[Dave W]

Unfortunately the manual does not show a chart with distances between marks and their possible culprits like my HP does. It might be a lump of hardened toner on one of the rollers in the fusing unit.

[The Natural Philosopher]

But that will print dots identifyinhg WHICH roller is 'near the dot' and so telling you which one to remove and clean

[Grumps]

'Tis a good plan. But the colour rollers are the easiest to examine and they're all OK.

[Grumps]

I got the service manual of another Brother printer which looks very similar. The fusing unit is my guess now, but this is the only roller unit that does not just pull out. Some screws require undoing - I'll have a go when we get more daylight. Ta.

[The Natural Philosopher]

ah. bugger :-)

pickup roller then ?

[Brian Gaff (Sofa]

Yes, that is where that dead fly went then, syndrome. Brian

[Grumps]

An update. A Youtube video described the process (thank goodness for fast forward) of removing the fuser unit. That is where the problem is. There appears to be a blister (deffo not dirt) on the heat roller.

It works, and I don't print much, so it'll have to do unless I can get some reasonably priced spares. It'd be an easy job to fix.

Thanks for all of your suggestions.

[newshound]

Good result. I have a couple of Brothers and they are both pretty good. IME all the printer manufacturers have both user and service manuals online. Ignore third party web sites that claim "we have all the manuals", they are invariably crap.

[Dave W]

A blister? On a metal roller? The roller must be very thin metal - perhaps the blister can be hammered or squeezed flat? Or is the blister on the surface of the metal, like a solder blob, that could be filed away?

[Paul]

The fuser unit has a thermal switch on it, and apparently toner can pile up on the surface of that part. Perhaps the fuser unit strayed outside it's intended temperature range.

Paul

[Grumps]

That's the video I found too.

The heated roller seems to have a squishy(ish) black sleeve over the metal part. I've tried to push the blister down, but it won't go flat.

This image shows a far more serious failure:

When I get my replacement rollers, I'll completely strip the old one down to see what went wrong.

[Paul]

The fuser should not need to get nearly as hot, as in the black & white Xerox machine days.

Modern color toners use some sort of organics, with stuff added to it. The toner particles melt and fuse at a lower temperature point. This allows using materials in the paper path, that only have to take that lower temperature.

Whatever that sleeve material is, maybe it cannot handle too much of a temperature excursion. There are some plastics that work at up to 200C (if the sleeve was plastic).

Paul

[Andrew]