HP LJ4000 prints very lightly near left margin.

This problem had been happening intermittently. Now it's becoming more frequent and annoying. A sample is here:

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Along with the vertical streak of light type that runs the entire length of the page near the left margin, that same streak has a rough texture to it when your run your finger over it. The rest of the paper feels normal. Any ideas what could be causing this? Would cleaning the laser scanner unit be the next logical step as explained here?

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Thanks for your reply.

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David Farber 
Los Osos, CA
Reply to
David Farber
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The roughness is probably iron filings, the so-called developer. Maybe dampness, maybe contamination, its not flowing correctly, plus loss of the material leading to gaps and consequent non moving of the toner in one section. Try removing the cartridge and shaking about , to redistribute the filings

Reply to
N_Cook

Just now, I gave the toner cartridge a good shaking. I'll let you know if things improve.

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David Farber 
Los Osos, CA
Reply to
David Farber

The fuser roller or film has a layer of caked on and possibly burned in toner imbedded in it. It should be visible if you remove the fuser assembly. The printer looks like it's printing normally, but the toner is not sticking to the paper and is getting sprinkled all over the affected area. It also appears that you have the same problem on the other edge of the page. My guess is that you dumped some toner on the page from the toner cartridge.

What to do about it:

  1. Remove everything you can from the printer. Paper tray, toner cart, fuser roller, etc. Find an air compressor that doesn't spray water and blow out the printer. My guess(tm) is that it's quite dirty in there. Try not to get the nozzle too close to anything fragile or you'll break things.

  1. Inspect the fuser roller. It should be a consistent color across its length and not have any caked on toner at the ends. If it does, find a PLASTIC scraper and carefully scrape off the melted plastic toner. It will not stock to the drum and should fall off easily. Also, remove any melted toner stuck to the rubber rollers. You may need to turn the rollers by hand. Blow out any remaining debris.

  2. If cleaning the fuser doesn't fix the problem, or the fuser roller looks burned at the ends, you can either replace just the fuser film (or sleeve), or get a replacement or exchange fuser assembly.

  1. If the amount of dumped toner is substantial, it's probably also imbedded in the rubber feed rollers. They can be cleaned, but with such an old printer, methinks a maintenance kit with separation pads would be best:

I some HP 4000/4050 parts in stock if you don't mind ancient inventory. Email for details.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

How to remove and replace the fuser assembly and install new rollers in an HP 4000/4050: (6:25) (3:56) Plenty other videos on the topic.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

HP manuals will tell you what item is faulty based on the spacing of the repeated image. Each roller that can affect the image is a different size for this reason. Clean the relevant roller.

NT

Reply to
tabbypurr

Maybe it must have improved, but its still probably an indication that the cartridge is low and needs refilling/replacing.

Reply to
bruce2bowser

Reply to
David Farber

Hi Jeff,

You said: My guess is that you dumped some toner on

I don't know how to interpret your guess. :-)

Here are pictures of the left side of the rollers in the fuser assembly:

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I didn't see anything that was caked on but you can definitely see that the there are some inconsistencies in the color.of roller-1. Roller-2 looked rather normal except there seemed to be some waviness in the way it reflected light as I was looking at with a magnifying glass.

I decided to swap out the fuser with another LJ4000. I also created a "printer cleaning page" via the control panel and so far it's printing better.

Thanks for your reply.

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David Farber 
Los Osos, CA
Reply to
David Farber

There were times that parts of the image were reprinted (think old TV with rabbit ears receiving a secondary bounced signal) at a specific interval.

I used the repetitive defects ruler in the manual which is also shown here:

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The spacing of the defect was 76mm which put the fuser roller as one of the primary suspects. I decided to swap out the fuser assembly with another machine that I had which wasn't in service and the problem seems to have been corrected for now.

Thanks for your reply.

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David Farber 
Los Osos, CA
Reply to
David Farber

The companies the refill toner cartridges tend to overfill the cartridges and forget to empty the overflow bins. The result is that a replacement cartridge will dump some toner onto the page or mechanism. This eventually gets to the fuser roller, which melts the toner onto the paper, rollers, gears, etc.

The fuser sleeve is definitely burned and in need of replacement. You can replace the sleeve yourself but make sure you smear some of the included silicon grease under the sleeve.

The red rubber pressure roller looks just fine. There's a little black spec of melted toner imbedded into the red roller, which is easily removed. I can't be sure, but it looks like you have some scratch marks on the red roller surface. These are caused by melted toner accumulating in places that are stationary relative to the roller, and scrape the surface. At this point, it probably won't cause any problems, except that the grooves tend to attract and retain loose toner that eventually melts and sticks to the surface. Spin the red roller to be sure it's clean.

No clue on the waviness. I've seen that happen along with a wrinkled roller surface. They usually go together. However, there's no evidence of wrinkling in your photo. When it does wrinkle, it can't be easily fixed and needs to be replaced. Note that the 4000 series fuser rebuild kits usually include just the fuser sleeve, the red rubber pressure roller, and some silicon grease.

Better as in there is still toner crud on the edges? Not good enough. Did you tear it apart and blow the loose toner out of the guts? Black toner on black plastic is difficult to see.

My guess(tm) is your replacement fuser assembly is only a little better condition that the one you replaced. They're not very difficult to take apart and clean, but it does take some care and there are a few parts that are easy to break. Learn by Destroying perhaps?

Good luck.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Reply to
Jeff Liebermann

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