Laser Printer Repair Experts

I just received a color laser printer from a relative that is brand new in the box. It is a Dell 2150CDN and was purchased in 2011.

Today, I opened the box up and set the printer up, and everything works great - except that there is a defect printed on every page - even blank pages, that has me stumped.

There are cleaning procedures within the User/Maintenance menu of the printer, and I have performed all the ones available, but the defect persists.

Here are some images that illustrate the defect:

Full page - Flat

Full page - brightness/contrast push


Can anyone suggest where the defect is being generated and what can be done about it?


Did you replace the toner cartridges and/or imaging drum(s) with new ones? I’d be very suspicious of expendables at this point.

Just my two cents’ worth.


No, they are new. Well…they are unused.

That’s what I’m looking for: what has gone bad in 7 years of sitting in a box. Is it the toner cartridges? The imaging drum(s)? Fuser?

I’m hoping for a quick fix like “wipe the imaging drum(s) with IPA and you’re good to go” or something like that.

I can replace the expendables, but I don’t want to do that without having a very good idea that it will fix the problem.

It looks like the print heads… since you think it’s a laser printer, that suggests that it’s the optical path. I don’t think anything else could give the multi-color 2-dimensional repeating pattern.

To clean the optics, blow softly, use alcohol and lens tissue, or as a last resort, alcohol and Q-tips. Lens and mirror coatings can be easily damaged - test a small area first. Don’t dissassmble – you’ll never get the alignment exactly right.

Have you checked the service manual or troubleshooting guide of the user manual for the printer? In my experience (mostly with HP printers), the distance between the defect can pinpoint the cause. For (a made-up) example, if it occurs every 3.5cm, that points to the toner cartridge, which has a cylinder that is 3.5cm in circumference.


It’s a damaged cyan drum.
And, in this printer, the only way to fix it is to replace them all.

It’s periodic in nature - cut a small piece of paper the same length as the distance between the start of two consecutive marks - roll that paper in a loop - you’re probably looking for a fault in or on a component with that diameter - probably a roller, a transfer drum or something similar.

It looks like it’s affecting both yellow and cyan layers, but with a very similar pattern on both - so I would be looking for something that’s common to both those paths.

I had a laser printer that did something like this and it turned out to be a bump on one of the rollers that distributes the toner out of the cartridge, but mine was more blurry/irregular than yours - so I would be inclined to look at later parts of the process.


Why all of them?

It looks like some toner may have hardened and gotten stuck after sitting for so long. A quick look on the web says that unopened toner may last 1-2 years. Even if you get the defect fixed, the toner cartridges would probably need to be replaced with fresh ones.

This might be an interesting project to fix it, but financially you’ll likely be better off getting a new printer. If you need a cheap color printer, craigslist can often be a good source. Many people get rid of their printer rather than buy new color cartridges.

Yeah, that’s what I’m thinking. I don’t really need a laser (or LED) printer and I am loathe to spend any money on this.

It is a pity, though. It’s essentially brand new, and I was hoping for a quick fix.

All 4 of them come as a single assembly.

ETA: a printer repair shop with access to spares might be able to swap out a single drum, but they are not designed to be user-replaceable individually.

If you don’t need color, you can get a monochrome laser printer for under a hundred bucks. It’s useful for occasional print jobs at home. And laser toner, unlike inkjet fluid, doesn’t dry out over time. I had my first laser printer for over twelve years and only replaced it because it finally needed to have the toner cartridge replaced. It would have cost me about eighty bucks for a new toner cartridge and rather than put that money into a printer with only 300x300 dpi resolution (I think 600x600dpi is now standard), I recycled the printer and bought a new one.

It is remarkable how regular and geometric the defects are. This is occurring in the cyan and yellow colors, and a very little black.

Here’s a closeup:

Here’s the same image with color inverted:

You’ll notice that the yellow and cyan defects are the same shape.

Are you just printing a blank page and these defects are coming out? If so, try printing blank pages over and over and see if the defects lighten up. Perhaps this gunk will eventually get cleaned off on its own.

Laser printers are better long term value than inkjet printers. The cost per page is usually significantly less.

Yup - just a blank Word document.

Cleaned off on its own? Nope - I was hoping that would happen, but it’s not.

I wouldn’t mind spending a little money to fix this, but I won’t spend a lot. The genuine set of Dell toner cartridges cost $375 on Amazon. That’s as much or more than the printer cost 7 years ago, I think. That’s not gonna happen.

It’s periodic in two dimensions: both down the page and across the page. Rollers and drums don’t do that.