Print or Copy Quality, toner

How to Remove Repetitive Image Defects from an HP Toner Cartridge

Often when removing the toner cartridge for a paper jam,  shaking it to get a few more prints or removing it while performing printer maintenance the toner stirs up and a small bit of toner or even a speck of unknown material will adhere to the charge roller inside the cartridge.  This causes a small dot to appear on all of your prints.  These dots are all “in-line” and have identical spacing.  HP calls this a repetitive image defect.

All HP all-in-one laser printer toner cartridges are affected and this problem can arise.  Once this happens you really have nothing to lose but to try this fix.  It is definitely worth a try as you would have to replace the  cartridge if you didn’t want a dot on all of your documents.   The cost for these cartridges are quite expensive.    If you just purchased the cartridge you can try to have it replaced under warranty.  NOTE:  When removing the toner cartridge for whatever reason, never set the cartridge upside down.  Place it right side up.  Always set it down gently.

How to tell if it is the Charge Roller Causing the Issue
You will know it is caused by the Charge Roller by understanding the image defect ruler.  The spacing on most laser printers will be 37.7mm or 1.5 inches between each dot.

Primary Charging Roller Repetitive Defects
Primary Charging Roller Repetitive Defects
Primary Charging Roller
Primary Charging Roller

How to Fix It

What you will need
You will need a Q-Tip,  writing pen and a flashlight.
Also you will need a sample of the print job with the image defect.
Q-Tips      Pen   Flashlight

Line up the defect page, centering it with the charge roller on the toner cartridge.
Line up the defect page, centering it with the charge roller on the toner cartridge. The Charging Roller is visible through the shutter slit. This is where the laser unit directs the beam to create the Image.
Mark the toner cartridge following the image defect or "DOT" so you will know where to clean the charge roller.
Mark the toner cartridge following the image defect or “DOT” so you will know where to clean the charge roller.
Mark the location of the defect with a pen.
Mark the location of the defect with a pen.


Shine a flash light into the shutter and locate the dot and clean it with the Q-Tip. WARNING: Do not use and type of chemical , water or solvent as this will destroy the charge roller.
Shine a flash light into the shutter and locate the dot on the charge roller and clean it with the Q-Tip.  WARNING:  Do not use any type of chemical , water or solvent as this will destroy the charge roller.

Next re-install the toner cartridge and print a configuration page.  If the dot is still there, redo the previous steps until the dot is gone.  Have patience.  It sometimes takes several tries to get rid of the dot.  I have had a 100% success rate, so don’t give up.  Following is a list of directions to print a configuration.  You can google the directions if you do not have a service manual for your particular machine.

Printing the Configuration, Short List

Print the Configuration page LaserJet 4100
Press Menu until INFORMATION MENU appears.

Press Item until PRINT CONFIGURATION appears.
Press Select to print the page. Note the number of pages since last maintenance.

Print the Configuration page  P3005
1. Press Menu.
2. Press to highlight INFORMATION, and then press .
3. Press to highlight PRINT CONFIGURATION, and then press .

Print the configuration page P3015
1. Press the Menu button .
2. Press the down arrow button or the up arrow button to navigate to the INFORMATION menu, and then press the OK button.
3. Press the down arrow button or the up arrow button to highlight the PRINT CONFIGURATION option, and then press the OK button to print the page.

Print the Configuration page Laser Jet M601,602 and 603
1. Press the Home button.
2. Open the following menus:
● Administration
● Reports
● Configuration/Status Pages
3. Scroll to the Configuration Page item, and then press the OK button.







Print or Copy Quality

HP Color LaserJet 3600 Won’t Stop Calibrating

This article is in regards to the issue of continuous calibration in the HP Color Laser Jet 3600 series printers.
Other models affected are
Color Laser Jet 3000, 3600, 3800 printers.

Problem:  Continuous Calibration

3600 calibration problem
3600 calibration problem

Calibrating and the Electrostatic transfer belt (ETB)
When your printer calibrates, it is checking for  a toner patch that is laid on the ETB or transfer belt assembly.  It is also adjusting the location or registration of where each color is laid.

If you change one of the toner cartridges  or the transfer belt it will automatically calibrate itself.  It will sound like it is making a copy and you will see Calibrating on the display.  With this calibration issue the problem is that it  will never stop calibrating  or come to ready.

You can calibrate it yourself.

Calibrating the printer

Calibration is a printer function that optimizes print quality. If you experience any print-quality problems, calibrate the printer.
1. Press Menu.
2. Press to highlight CONFIGURE DEVICE, and then press .
3. Press to highlight PRINT QUALITY, and then press .
4. Press to highlight FULL CALIBRATE NOW, and then press .

When the machine begins calibrating it looks for a patch of toner on the ETB.  If it doesn’t sense it or if the patch is light the machine will not complete the calibration.

ETB toner calibrating patches
ETB toner calibrating patches; Notice there is no Cyan on the belt. This machine had the Cyan seal pull tab left in it.

Color Registration
The calibration also takes sensor readings with the color mis-registration sensor.  It checks each color and adjusts them so that they are aligned.   If the printer didn’t calibrate and align the colors the machine wouldn’t know where to lay down each color and your image would be offset, blurry and just not good.

Trouble-shooting Steps
Inspect each toner cartridge and make sure that the pull seal strip is removed.   Make sure that the pull tape didn’t break off inside.  If you believe it may have broken off inside you should replace the toner cartridge.   You should be able to get credit for the cartridge as defective.

Pull tab seal left in cartridge
Pull tab seal left in cartridge

Testing the Toner Cartridges
You can let it begin calibrating then stop it by opening the front door,  Look on the ETB.  You should have all four colors laid on the belt.  If each toner cartridge is working correctly it will be laid on the belt.  If you can see it but it is much lighter  than the others or its not present there is a problem.  See image below

ETB toner calibrating patches
ETB toner calibrating patches;

It is possible that the ETB may have an issue such as a bad sensor, so you may have to replace the ETB.  I would trouble shoot with the hopes that this is not the issue, but it could be the case.  There is a way to bypass the calibration and get it to come to ready though the print quality may be horrible.  If you are out of ideas it can’t hurt to try this.

To Skip Calibration
1. Turn the printer off and then on.
2. When the printer begins its initialization sequence, press and hold  the “DOWN”  arrow until all LEDs are lit.
3. Press the “UP” arrow one time, and then press “Menu”.
4. Press the “UP” or “DOWN” arrow until it comes to  “Skip Calibration”.
5. Press “CHECK”.

NOTE:  Do not press check when it is displaying  “NVRAM INIT”!

The problem for me has always been a  bad toner cartridge or a toner cartridge with the seal left in it.  It really is a tricky problem for even a technician so I wish you luck.  I believe that this problem has to be a firmware issue and I don’t believe HP will ever fix it.  It is such an old printer at this point it would be senseless  to spend the money and yet there are many people that still have these printers.

Print or Copy Quality

Symptoms of a Bad Drum

A photoconductor is the part in a copy machine that helps develop the image for each copy.  It works on the principle of static electricity.  Analog copiers use light from mirrors and digital copiers use a laser to discharge non-image areas to create the invisable latent image.  Then toner is introduced that is opposite charge that of the drum and is basically sucked onto the drum.

Photoconductor Process
Photoconductor Process

One of the most popular things for an inexperienced and/or a dishonest copier repair person to say is,”you need a new drum.”  When in reality your equipment just needs to be cleaned.  They are either lazy, inexperienced or crooked.  Many times all that needs to be changed is the drum blade.  Think of the drum blade as a windshield wiper on your car.  After a lot of use it quits working properly and leaves streaks.  It is the same with a drum blade.

Essentially,  if you see a hole or a nasty scratch on your drum, you can’t fix it.  You wont be able to get that mark off of there.  But, if you see a line or mark on your drum, take a clean soft cloth (no chemicals or liquid) and see if you can wipe it off. If it wipes off then replacing the drum blade will help.

If you have a question regarding the replacement of your photoconductor or drum or to make sure if you need it replaced, post a comment here.  I am happy to give you my best advise.

Be sure to leave the Make and the Model and a good description of the copy quality and we can help.  Take a photo of the print or copy and email it to

Copiers, Print or Copy Quality

Symptoms of Bad Developer

Developer, what is it and what are the symptoms when it goes bad?

Developer consists of small iron particles (dual component).  The developer is mixed with augers churning all the time to keep the toner mixed evenly in the developer unit.  The Magnetic roller (mag roller) holds the toner and evenly distributes the toner.  Think of the developer as golf balls and inside the dimples of the golf ball the toner is carried (Developer is sometimes called Carrier) and evenly distributes it onto the drum or photoconductor.  When the developer material wears down the machine will dust with toner and cause backgrounding because it is unable to carry the toner as good as it did when it was new.   To help confirm that you need to replace the developer, there is a yield associated with it.  This yield could be 80,000 prints or 200,000 it all depends on the make and model of the equipment.  This is why a good service company utilizes a service record.  Then you can look to see when it was replaced last.


When changing the developer you must dump the old developer material out, vacuum and replace it with new material.
CAUTION: Some developer unit sensors are very sensitive and could pop by using a vacuum.  Better to just brush out the remainder of the developer than take a chance. You must always set the toner sensor before making copies and this takes knowing the simulation codes and how to set them.  It’s really not that hard you will just need the information.

Print or Copy Quality, printers, toner

Solving Image Problems on HP Laser Printers

There are several image related problems that can occur. If you want to save money and repair it yourself this article is for you. Read about the most common image related problems that HP Laser Printers have and how to resolve them.

Here are a few examples of image related problems:
Blank, Solid Black, Streaks, Double Images, Specks, Lines, Light Print, Dark Print, Blurred Image.  Here are some more examples.

Image Defects Example 1  Image Defects Example 2  Image Defects Example 3 Image Defects Example 4  Image Defects Example 5

Cartridges: Most Image defect problems are related to the toner cartridge. The first thing to do is try installing a new or different toner cartridge.  If you don’t have another cartridge to test it you can diagnose the problem another way.

Put a sheet of paper in tray 1.  Run a configuration page with your hand on the power switch. When the page reaches midway, turn the power off. You may have to do this a couple more times to get the timing correct. Now that you have stopped the paper midway, carefully remove the cartridge and the paper from the machine. Inspect it to see if the problem exists before it reached the fuser. If it does then it is in the cartridge, or possibly it could be in the Laser or scanner assembly. If it does not, then you have a bad fuser assembly. Remove the fuser and inspect it.

Cartridge problems are the most common cause of image related problems. I find more problems with remanufactured cartridges because the manufacturer is not replacing certain major components that cause the defects. Make sure they replace the drum. Also, look for companies that are ISO 9002/14001 certified and STMC certified. This will help weed out the undesirable cartridges. To be honest, I have seen a lot of OEM cartridges fail. Cartridges fail for several reasons, such as foreign objects getting into the cartridge causing lines, streaks and leaking. This can be resolved by being careful not to remove staples or paper clips in and around the machine. You should also have your machine cleaned. Vacuuming all of the paper and toner dust can help decrease this. Remember to only use a service vacuum that can handle the tiny particle size of toner.
Printing a Configuration page: You will always need to print a configuration page, and here are some reasons.
Image quality test, Page count, Serial number of machine, Configuration of printer, The last few errors, Jet Direct print server card is installed, Many others…

Here are a few instructions on how to print out a configuration page.
If you don’t see your model scroll through the menu on your printer and it should be easy to find.

HP LJ-4000/4050/4100
1 Press [Menu] until INFORMATION MENU appears.
2 Press [Item] until PRINT CONFIGURATION appears.
3 Press [Select] to print the Configuration Page.

HP LJ-4200/4250/4300/4350
1 Press (SELECT button) or the MENU button to open the menus.
2 Use (UP ARROW button) or (DOWN ARROW button) to scroll to INFORMATION, and then press the Check button (Select)
3 Use or to scroll to PRINT CONFIGURATION, and then press the check button.

HP LJ-8000/8100/8150
1 Press MENU until INFORMATION MENU appears.
2 Press ITEM until PRINT CONFIGURATION appears.
3 Press SELECT to print the configuration pages.

Image problems caused by the Fuser Assembly: Symptoms are, toner not fusing, streaking, double imaging.

Note: The 4200 series had a problem with the film getting ripped. You will see strands of plastic pieces coming out of the exit area. It will cause as an image defect, streaking and double imaging.

Diagnose: You can diagnose it by running a configuration page. Rub on the print. Is it flakey? Does the print rub off easy? If it does, it is probably the fuser. Remove and inspect it. You can inspect the film or roller. If you see any damage replacement is necessary.

Note: Most fusers on HP Laser Printers are very easy to remove. If you need instructions on how to remove and install them, I have free service guides, click here.

Regarding Light Prints:
If you have replaced your cartridge and you still have light prints or if you have light print over the entire page, you may have economy mode on. Go to quality menu and turn off. I would also try the transfer roller. This is also easy to replace, look in Maintenance kit installation procedure.

One last thing: If you have tried all of the above, there could be another problem. This procedure can be difficult for the average person to repair. It is cleaning the scanner or laser unit. If you are in a very dusty environment the mirror inside this assembly may be dirty. When the mirrors accumulate dust on them the image defect is light prints. I go into detail on cleaning the HP LJ-4000 scanner in another article I have. Click here and check it out.

Copiers, Print or Copy Quality

How to Fix lines on Your Copier

Why are there Lines on my Copies?
Have you ever made a copy and noticed that there are lines running down the length of the page? This article is about identifying image defects or lines that a Key-Operator (Person responsible for the equipment.) can fix on their own and lines that need a repair person to fix. You wouldn’t want to spend $75.00 to $150.00 for a technician to come out to just clean your glass, would you? No, I didn’t think so.

Xerox Photocopier
Xerox Photocopier

Slit Glass
With the age of Multi-Functional Printers, (MFP’s) comes new problems. Fax Machines, Digital Copiers and MFP’s all have one thing in common. They all have an item on them known as the “Slit Glass.” Each machine that uses a slit glass as a way to scan images will eventually get dirty and cause lines on copies along with transmitted faxes. These machines don’t scan the same way that older or analog copiers do. Analog copiers use the entire glass with mirrors to get the image to the Photoconductor. Digital copiers use the slit glass. It passes along this small area and uses mirrors that direct it to the CCD unit. The CCD unit then converts the analog information into digital information. When using the Document Feeder or Processor the original only passes over the slit glass. It does not get copied from glass where you lay down your original.

How to Determine if the Slit Glass is the Problem.
On Copiers, MFP’s and Fax Machines you can quickly diagnose if the slit glass is the problem.

First make a copy on the glass. If there are no lines showing, then make a copy through the Document Feeder or Processor. If there are lines on the copy then more than likely it is the Slit Glass causing the problem. I say more than likely because there are occasions where this may not be true.

Fax Machines and MFP’s:
First print a journal or a function list. To print these refer to your Operators Manual. If you don’t have a line, make a copy through the Document Feeder or Processor. If there are lines then your problem is the slit glass.

Digital Copiers and MFPs
This type of slit glass is easy to spot. Just lift the Document Feeder up and look for the small rectangular glass around 1 inch by 12 inches. Look at it carefully. If there is anything stuck on it, this will cause a line. The Image defect will look like a small pin sized line all the way across the page, although I’ve seen larger even 1 inch wide. The most common substance that I have found stuck to the glass is white-out. This happens because they don’t let it dry well before running it through the feeder. When it dries on the glass it doesn’t come off easily. Another issue is blobs of ink, again this is because of not allowing enough time for it to dry. Being impatient actually will cost you more time in the long run.

Cleaning the Slit Glass.
Cleaning the slit glass is easy but you need to pay close attention and be sure that you have removed all of it. Take your finger nail and scrape off as much as you can. Get a cotton towel and saturate it with alcohol. I also recommend using an alcohol swab. These come in little sealed pouches and are inexpensive and easy to find. Let the spot soak for a minute and this will loosen up the white out. Glass cleaner does not remove it as good as alcohol. There is something about alcohol that breaks down the white out. Next, go over it with a lint free cotton towel soaked with glass cleaner, and then dry it off to eliminate streaks. Never spray the liquid on to the glass because some of it may find its way inside the machine.

Fax Machines.
The slit glass on a fax machine may be a bit harder to get to. The document feeder or processor is normally under the control panel. Lift up the panel and shine a flash light on to the small slit glass. It is about 1 inch by 12 inches in diameter. Use the same technique to clean it.

You Cleaned the Slit- Glass but the Line is Still There.
Some times the blob of white out is really stuck on the slit glass. I have a procedure that is fool proof in finding where the spot is, because sometimes it is so small that you can’t see it. First, get the copy that has the line on it. Hold it directly and evenly on the slit glass. Look carefully and see if you can follow the line to the glass. This is where the spot is. One thing about this procedure. You must check it both ways. Turn the original 180 degrees and inspect it again because the image is reversed because of the lens. Now that you have found the spot you may have to use a solvent to get that spot off. These can be stubborn and difficult to remove. You can try WD-40. My technicians use a solvent called D-Ink (Coopers). D-Ink is very expensive but it works well. If you still have the line on your copies then you have another problem.

Calling for Service
Call a qualified repair person to come out and take a look. I recommend using a local independent repair company. Look them up in your Yellow Pages. I recommend an Independent because they usually are a smaller company and they will give you more personalized service. I hate those crazy phone systems, being stuck in a loop when trying to call for service. Most of the time they also have more experience and you won’t be paying for over- inflated hourly rates of an authorized dealer or huge corporation.

Other Line Problems
If you followed my tests and you have a line both copying from the glass and using the Document Feeder then you have another problem. I believe that it is always a good idea to have a good technician ready to call, but why spend money when it is something so simple anyone could do it. Here is a list of probable causes. Many things could be wrong so I am not going to go in too much in detail.

Possible Causes / Lines

Laser Printers, Laser and LED Fax Machines
Toner cartridge, Charge roller, paper or object stuck inside blocking the scanner, transfer roller, optics, and corona wire. Note: You can clean these but if you don’t know what you are doing you can damage something.

Inkjet Printers and Fax machines
Print head, Ink cartridge, dirty optics, paper or object stuck up inside machine blocking the print-head or optics.

Copier and MFP’s
Toner cartridge, Charge roller, paper or object stuck inside blocking the scanner, transfer roller, corona wire, and dirty optics. Note: You can clean these but if you don’t know what you are doing you may damage something.

I hope this article has helped you save some of your hard earned money. There really is no reason to spend money when you can just clean it yourself!

Print or Copy Quality, printers

Symptoms of a Dirty Scanner

LaserJet-4000/4050 Scanner
This article shows how to clean the Scanner on the Hewlett Packard 4000 series Laser Printers.

HP LaserJet 4000/4050 Scanner Assembly
HP LaserJet 4000/4050 Scanner Assembly

This service procedure needs to be done when the machine is in a dirty environment and the dust builds up on the mirror inside the scanner.

Sample of a Dirty Scanner
Sample of a Dirty Scanner

Symptoms of a dirty scanner:
Light prints even after you have tried a new toner cartridge. Mostly shows itself as light prints on one side of prints or streaks or wide blank lines. HP LJ-4250: Blank streak down the middle of page. Note:This procedure is basically the same for the Following LaserJet Models: 4000, 4050, 4100, 4200, 4300, 4250, 4350, P4015, P4515

Getting to the Scanner:Turn the power off and remove the power cord. Remove the right rear side cover. Push the cover toward the rear and it will slide out. Open the top cover and remove the toner cartridge. Remove the toner cartridge drive arm. Remove the Toner Cartridge Drive Arm by using needle-nose pliers to pinch the pin from its hinge on the Top Cover. Remove the four screws holding the Top Cover (two are behind the Rear Output Bin, near the top, and two are on top of the printer under the Top Cover). Squeeze the right front side of the Top Cover to remove it. It may be necessary to use a small flat-blade screwdriver to release the tab inside the small hole. Holding the output assembly in place (located toward the rear of the printer), remove the Top Cover. Disconnect the wiring connector(s).

Remove output assembly:
Facing the rear, pull up brass arm on the left side straight up. Pry the white tab on the right side and pull the output assembly up and out. Caution: Be careful of the sensor flag. When reinstalling make sure it rotates freely.

Removing the Scanner Cover:
Carefully remove the wiring connectors. Remove the cover of the scanner by removing the screws and using a small flat blade screwdriver to release the latches. Carefully remove the cover.

Cleaning the Mirror:
The only mirror you will be cleaning is the one that shines directly on to the drum in the toner cartridge. This mirror is at an angle. You need to clean the mirror from below. Use a Q-tip to clean it. Make sure you clean the edges really good. Reinstall everything in reverse order.

Copiers, Print or Copy Quality, toner

Copier Care 101

Reliable copying is a basic need of the office. By following some of these suggestions, you will enhance the reliability of your machine by minimizing down time and maximizing the return on your investment.

•Key Operator
Assign a key operator to your copier. The key operator must be able to handle simple problems and identify any break downs requiring service . When you have a consistent problem , notify your service department. Also, try and have patience. It will do you and the service company a world of good.

Xerox Photocopier
Xerox Photocopier

Carefully choose the location of your copier. Avoid situating the machine where it is likely to be jarred. You should avoid extremes in temperature, exposure to direct sunlight, open windows, air conditioners or heater units.

Heed the “add toner” indicator. When the toner in the machine is depleted, copy quality will degenerate. You might also damage the developer material inside the machine if you continue to use the machine. It is a good idea to have at least 1 extra bottle or container of toner at all times. Have the key operator call as soon as the last toner is used thereby avoiding costly down time.

•Paper Clips and Staples
Do not put staples or paper clips on top of or near the copier. Serious damage can occur such as a scratched drum or electrical short when one of these finds its way inside the machine. Keep beverages and other liquids away from the copier.

•Paper Jams
Approach paper jams with care. Do not use any tool or sharp object inside machine. Store paper in a dry area, humidity can cause paper jams and copy quality problems. Remove any damaged paper or dog-eared pieces before installation. Carefully fan the paper before installing it in the paper Cassette.

•Cleaning The Glass
Frequently clean the platen glass. Use glass cleaner but if you have a automatic document feeder it is recommended that you use an anti-static cleaner. (Brillianize ) can be bought at a hardware store.