HP LaserJet 4P

How to Identify and Fix Common Problems ?

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When your printer leaves black lines, the lines indicate that there are excess toner powders on the rollers or transfer belt within the printer. As the paper is moved along by the rollers and transfer belt, any excess powder left on them can result in lines being left on the paper.
The streaks or lines might be caused due to low ink levels in one or both ink cartridges. Check the ink levels using the HP Toolbox to determine if the ink cartridges are low on ink and need to be replaced.
Streaking is usually caused by a worn out drum unit or spent toner cartridge. Drum units are a consumable and only need to be replaced after the use of 3 or 4 toners. Not all printers use a separate toner and drum unit.
A printer printing lines on the page are normally caused by a blocked, dirty, or damaged print head. Blocked ink cartridge nozzles, or not removing protective seals correctly when you installed a new ink cartridge can also cause missing lines of print.
If you notice white or dark lines in your prints (also called banding), try these solutions before you reprint: Run a nozzle check to see if any of the print head nozzles are clogged. Then clean the print head, if necessary. Make sure the paper type setting matches the type of paper you loaded.
Conclusion. If your laser printer is causing horizontal black lines you either have a problem with the optics or the drum. Cleaning the optics and replacing the drum should fix the problem in most cases.
A horizontal line is a straight line that goes from left to right or right to left. In coordinate geometry, a line is said to be horizontal if two points on the line have the same Y- coordinate points. It comes from the term “horizon”. It means that the horizontal lines are always parallel to the horizon or the x-axis.
The black lines on your laptop screen are usually caused by a hardware issue. This can happen when the laptop is overheating, or if you have spilled liquids on it. If the problem is due to overheating, then you should try to keep the laptop cool by placing it in a well-ventilated area or in front of a fan.
For cleaning, HP recommends using HP Equipment Cleaning Wipes, but you can use an HP-approved lint-free wipe and deionized or distilled water. Note: If dark spots appear on back side of prints, clean drum screen. Note: If minilab prints more than 2000 prints each day, clean drum screen up to twice daily.
Streaks and unwanted lines could mean that the printer heads are out of alignment. There`s an alignment tool in the printer`s control panel. If that`s not the issue then the printer is dirty. Printer ink stripes may appear along the edges of the paper, which means there`s ink on the rollers and other parts.
HP has determined that 99% of all lines and streaks on copies made by feeding the original documents through the ADF are caused by debris on the ADF glass. Debris can include dust, paper or toner dust, residue from sticky note adhesive, correction fluid or tape, ink, fingerprints, and more.
The band-shaped “stripes” are called “horizontal bands” or “banding.” Horizontal bands are caused by the subtle changes in the movement distance that occur when feeding the media depending on the media`s thickness. We recommend making corrections to match the media you are using.
Horizontal and Vertical Lines

Horizontal lines are lines drawn from left to right or right to left and are parallel to the x-axis. Vertical lines are lines drawn up and down and are parallel to the y-axis.

Horizontal line is a straight line that is mapped from left to right, whereas the vertical is a straight line that is mapped from top to bottom. In coordinate geometry, the line parallel to the x-axis is called horizontal line and the line which is parallel to the y-axis is called vertical line.
Why is it important to clean a laser printer? Printing is vital to all businesses so ensuring your laser printer is thoroughly cleaned is crucial as it allows your machine to continue working efficiently. Cleaning a laser printer is easy with the correct equipment, however they are prone to dust and debris.
If your PC or the LCD screen on your printer is telling you that your ink cartridges are full but no ink is passing through to the paper, then it`s most likely that you are dealing with a clogged printhead. Blurry documents and images that appear faded are also signs that it`s time to remove the excess ink.
The sponge end of a blocked printer head can be cleaned with only one liquid other than water. This liquid is isopropyl alcohol. Isopropyl alcohol isn`t strong enough to melt the sponge but is still strong enough to dissolve the ink inside the blocked printer head.
Print head cleaning consumes some ink. To avoid wasting ink, clean the print head only if print quality declines; for example, if the printout is blurry or the color is incorrect or missing.
A vertical line is a line extending up and down. On a table (like the one shown to the right), the legs of the table are vertical lines. The y-axis is an example of a vertical line.
Conclusion. If your laser printer is causing horizontal black lines you either have a problem with the optics or the drum. Cleaning the optics and replacing the drum should fix the problem in most cases.
If your printouts are blurry or smeared, try these solutions: Make sure your paper is not damp, curled, old, or loaded incorrectly in your product. Use a support sheet with special paper, or load special paper one sheet at a time. Make sure your paper meets the specifications for your product.
A vertical line is always a line that runs from top to bottom, or, from bottom to top. Standing lines are also a type of vertical line that runs vertically. We usually draw vertical lines between the bases of a trapezoid or a parallelogram….
Conclusion. If your laser printer is causing horizontal black lines you either have a problem with the optics or the drum. Cleaning the optics and replacing the drum should fix the problem in most cases.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

evenly spaced horizontal lines on hp laserjet III printout
ANSWER : The lines would be a toner cartridge problem. Which paper tray? The MF tray or the optional paper cassette?

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HP LaserJet 4P

HP Laserjet 1320tn printing grey instead of black
ANSWER : Try this test. Put a page into the manual feeder and do that same test. When the end of the page is just about to enter the printer, open the lid. Take out the toner cartridge and pull back the shutter. Look at the image and see if it is black. The explanation is that there is high voltage going to both the toner cartridge and the charge transfer roller below it. If the image on the drum is black, then the fault is at the transfer roller not getting enough high voltage. The transfer roller pulls the image off of the drum and down onto the paper. It would not be a laser scanner problem as any issue with it would not result in an overall gray image, but combination of gray and black. It will probably turn out to be a bad HV power supply, which will need replacement. I’ve never seen this particular problem on this model.

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HP LaserJet 4P

How to copy a card slot in HP laserjet 4250N
ANSWER : None that I know of, using a computer is likely your best option but I never attempted it.

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HP LaserJet 4P

HP Laserjet 4250 – RFU LOAD ERROR
ANSWER : Italiano:

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HP LaserJet 4P

HP Laserjet 4200 50.2 Fuser error
ANSWER : if you are using a good fuser the next part to try would be low voltage power supply

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HP LaserJet 4P

What repair needs to be done for a "50 needs repair" message on an HP Laserjet IIIP?
ANSWER : I don’t know what you mean by good toner cartridges. They haven’t been built in about 10 years, so if they are new OEMs in the box, they are guaranteed to fail. The 50 error on that printer is mostly a burned out fuser lamp. This site was sold, so as you can see, there are no more kits available.

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HP LaserJet 4P

HP laser jet 3015 "Upgrade Error Call HP Support"
ANSWER : rgtr

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HP LaserJet 4P

HP Laserjet M3035xs RFU Upgrade
ANSWER : There’s no way.

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HP LaserJet 4P