HP LaserJet 4

How to Identify and Fix Common Problems ?

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Faint, streaky or spotty prints are all common signs of a clog but a simple cleaning can usually get your HP ink cartridges working again. Printheads clog due to infrequent cartridge use. If you regularly go a few weeks without printing, your cartridges will eventually dry out and need to be replaced.
Check the toner darkness settings.

Sometimes light print can be remedied by simply changing the toner darkness setting in the printer. To change the setting, go to MENU>>SETTINGS>>QUALITY MENU>>TONER DARKNESS. Increase the darkness and send a test print to see if that fixes the issue.

How long does HP toner last? HP toner cartridges can last up to two years in their sealed packaging. Even after two years you may still get some use out of the cartridge, so it may be worth trying even after the fact. Your printer will display a “low cartridge” message when a specific cartridge needs to be replaced.
A common cause of faded, faint printouts from your inkjet printer is dried ink particles causing a blockage in your printer. The printheads on an ink cartridge can be become blocked if the printer is not used for a period of time, so it is recommended to print a few pages each month to maintain the print quality.
Inkjet prints are prone to fading over time, which can be accelerated by exposure to pollutants. Pollutants such as ozone, nitrogen oxides, and sulfur dioxide can cause fading and degradation of inkjet prints.
In the [Advanced Settings] dialog box, select [List of Settings] [Toner Density] [Adjust] → click [Details]. Adjust the density for each color → click [OK].
Color Laser Printer or Black & White Laser Printer

As print quality goes down over time, this will be a reason to replace the color printer. We find a black and white printer can sometimes last 10 years or more and most color laser printers are replaced every 3 to 5 years.

Laser printers use toner which will not dry out the same way an ink cartridge does. Unlike ink, which is liquid-based, toner is a dry powder composed of plastic components so it will not dry out. You can leave a toner cartridge in your printer for weeks untouched and it should still print.
Benefits of using toner and laser printers

Furthermore, toner does not dry up in the same way that printer inks do if you don`t print so often, saving time and money.

After you print the image the colour looks great, but after you fix it, the print looks dull? The temperature is set too high on the heat press. Make sure you test the temperature using heat test strips or a heat gun. If the temperature is too hot, it could scorch the shirts and the ink.
If a fuser unit is not heating the toner powder correctly, ghost images can appear when printing. You can check to see if the fuser unit or drum unit is causing the ghosting by having a look at the ghosted images.
If you still find your laser printer not printing dark enough, toner might have built up on the laser print rollers. To prevent this from happening and lightening your laser printouts, make sure that you run a printer cleaning sheet through your laser printer occasionally to keep your laser printer fresh.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Prints blank pages, won't print from computer
ANSWER : Don’t know why you replaced the fuser, but assuming you had print before, then it must have been something you did during the procedure. Only thing I can suggest is to recheck your work. Just because you reinstalled a connector doesn’t mean that it is seated firmly enough to work. Any flat ribbon connectors that you removed and reinstalled, check to see that the contacts are all flat and not peeled back.

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HP LaserJet 4

when printing front and back, the front will print well but the back will fade
ANSWER : It happens because second side voltage is much higher and the board breaks. Are you getting this issue in auto duplex only, or same error you are getting when you print second side manually?

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HP LaserJet 4

Faint printing with gaps
ANSWER : Don’t know what you mean by cleaned the nozzles. If you used the printer function to do that, it was a waste time and ink. You should buy a printhead cleaning kit off of eBay and do it right.

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HP LaserJet 4

Print file sent but no printing occurs
ANSWER : Been working on these since they first were released. Never seen a problem like yours. If it happens again, try doing an engine test, as it bypasses the formatter board. The engine test is located at the right side of the manual tray opening. Look for a hole in the side wall. Stick something like a paper clip into it to actuate the test button. It will then print a lined test page. If it does that, then it points to the formatter board as the cause of your problem.

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HP LaserJet 4

My printer feeds through one piece of paper all the way and then a half piece of paper and stops. I pull out the paper to stop the paper jam and then it prints but sounds rough. After printing, it doesn't feed the paper all the way through.
ANSWER : And the first 2 sheets, the full and half sheet that go through first, are blank.

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HP LaserJet 4

HP Deskjet 640c wont print??
ANSWER : yes

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HP LaserJet 4

Epson Artisan 835 print head cleaning question
ANSWER : I had the same problem. After reading the comments, I tried Liquid Wrench spray. 1st try got about sixty percent improvement. Tried again this time I let it set for about 10 min then did a head cleaning. Completely solved the problem. I am a little concerned about its use on plastic. So far so good.

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HP LaserJet 4

My printing come out blurred
ANSWER : doris…There are usually 2 reasons for blurry output on this printer. First, make sure that the alignment is correct. You can get to it from the maintenance tab on the software that came with the printer. The other common cause of blurring is debris under the printhead. Hope this helps.

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HP LaserJet 4