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Remanufacturing the HP CP 2025 Black and Color Toner cartridges

• Feb 01, 2009

These cartridges also use chips that’s should be replaced each cycle for the cartridges to have full functionality.

The printers based on the CP2025 engine are the:

HP Color LaserJet CP 2025n
HP Color LaserJet CP 2025dn
HP Color LaserJet CP 2025x
HP Color LaserJet CP 2020 (Asia only)

The cartridges used in these machines are the:

CB530A (Black) 3,500 pages — $115.99 List*
CB531A (Cyan) 2,800 pages — $114.99 List*
CB533A (Magenta) 2,800 pages — $114.99 List*
CB532A (Yellow) 2,800 pages — $114.99 List*
* Pricing current as of December 2008.

HP-CP2025 Color Printing Theory

The Color toner cartridge printing process happens in s series of stages or steps. For the purpose of this article, we will call them stages. Figure 2 shows the basic layout of the cartridges and how they relate to one-another and the printer. Note that while this is still a single pass system, the layout is completely different from any previous Canon/HP machines. Figure 3 shows the complete image formation process

In the first stage, the Primary Charge Roller (PCR) places a uniform negative DC voltage on the OPC drum surface. The amount of the negative DC voltage placed on the drum is controlled by the printer’s intensity setting. See Figure 4.

In the second stage, the laser beam is fired onto a rotating mirror (called the scanner). As the mirror rotates, the beam is reflected into a set of focusing lenses. The beam then strikes the drums surface, reducing the negative charge and leaving a latent electrostatic image on the drum. The areas where the laser did not strike the drum will retain the higher negative charge. Technology has advanced tremendously in these machines as there is one laser/scanner unit for all four colors. The laser/scanner unit contains one scanning motor and mirror with four separate lasers. See Figures 5 and 6.

The third or developing stage is where the toner is developed on the drum by the developing section (or supply chamber), which contains the toner particles. The development stage is actually made up of two steps: toner charging, and the actual development. In the toner charging stage, the toner stirring blade turns inside the hopper. As it turns, friction causes a negative potential to develop on the toner. In addition, a foam feed roller brings the toner to the developer roller and also places a negative charge on the toner. These two charges help ensure a uniform charge on the toner.

Once the toner is properly charged, the toner will coat the developer roller. The toner is also held onto and attracted to the developer roller by another negative DC bias voltage. This voltage is controlled by the printer’s intensity setting and causes either more or less toner to be attracted by the developer roller. This in turn will either increase or decrease the print density. The amount of toner on the developer roller is controlled by the doctor blade, which uses pressure to keep the amount of toner on the roller constant.

As the laser exposed areas of the OPC Drum approach the developer roller, the toner particles are attracted to the drum’s surface due to the opposite voltage potentials of the toner, and laser exposed areas of the OPC drum. See Figure 7.

The fourth stage is the transfer stage. This is where there are some large differences from monochrome printers and also from other color lasers.

In the Primary transfer stage the transfer pad (Not a roller in this case) which is located directly opposite each OPC drum, places a positive DC bias charge on the back of the ITB or Image Transfer Belt. Each toner cartridge has a separate transfer charge pad.

The image is transferred from the drum directly to the ITB. This process is repeated for each color cartridge in the following order: Yellow, Magenta, Cyan, and Black. At the same time, the paper is moving between the Secondary transfer roller and the ITB. As the ITB passes the Secondary transfer roller, the positive charge is picked up, and draws the negatively charged toner off the Belt and onto the paper. See Figure 8.

The paper separates from the ITB belt as the belt reaches the top of its path and turns back down to start the process again. The static charge on the back of the paper is decreased with static charge eliminator. This helps stabilize the paper feed, and also prevents toner flares (spots) under low temperature and low humidity conditions. See Figure 9.

In the fifth stage, the image is then fused onto the paper by the fuser assembly. The fuser Assembly is comprised of the upper heating assembly and lower pressure roller. The lower pressure roller presses the page up into the upper heating assembly which then melts the toner into the paper. This heating assembly consists of a flexible sleeve with a ceramic heating coil inside. This type of fuser affords "instant on” fusing with little to no wait time, and low power consumption. See Figure 10.

ITB Cleaning

The ITB is cleaned by both the ITB cleaning Roller, and the ITB Cleaning brush. Both the roller and brush have a DC positive bias placed on them which in turn places a positive DC Bias on the residual toner. The Residual toner is then picked up by the OPC drum (Because of the positive bias) and then cleaned off the drum by the wiper blade. See Figure 11.

OPC Drum Cleaning

The drum is cleaned after the image is transferred to the paper by the wiper blade. This part is fairly standard; the wiper blade scrapes the toner off the drum, and the recovery blade guides it into the waste chamber. See Figure 12.

Printer Calibration

At the start of all this is the cartridge detection process, toner level detection, and then the calibration cycle. The printer will calibrate itself whenever the printer is turned on (Within 15 minutes), when a new toner cartridge is installed and after 48 hours of run time. Calibration consists of a solid block and halftone of each color being printed to the ITB. As the printed areas get to the top of the belt, a sensor will detect them, measure the density, and adjust the printer accordingly. All of the calibration time settings are user controllable.

Taking test prints, cartridge troubleshooting as well as minor printer troubleshooting will be covered at the end of this article.

Remanufacturing instructions

Required Tools

1) Toner approved vacuum.
2) A small screw driver (Common Style)
3) A Phillips head screwdriver
4) Needle Nose Pliers

Supplies Required

1) CP2025 Dedicated Color Toner
2) New replacement chip
3) New Long Life CP2025 Drum
4) New Wiper Blade
5) New toner feed roller [Optional]
6) New PCR [Optional]
7) New Doctor Blade [Optional]
8) Drum Cover
9) Lint free Cloths
10) Conductive grease

[1] With the label on top and facing you, remove the two screws from the left side end cap. Remove the end cap. See Figures 13 and 14.

[2] On the right side, remove the two screws and end cap. Be careful! The two halves will start to separate, and the drum will come loose! See Figures 15, 16 and 17.

[3] Flip the waste chamber upside down, and remove the drum. See Figure 18.

[4] Remove the PCR. Clean with your preferred PCR cleaner, and place aside. See Figure 19.

[5] Remove the two screws and wiper blade. See Figures 20 and 21.

[6] Clean out all the waste toner from the chamber. Make sure all the wiper blade seals are clean. See Figures 22, 23 and 24.

[7] Coat the new wiper blade with your preferred lubricant and install. Install the two screws. See Figure 25.

[8] Install the cleaned PCR. Make sure to place a small amount of conductive grease on the black PCR holder. See Figures 26 and 27.

[9] On the Supply chamber, remove the two screws from the gear side end cap. Lift up on the tab as shown and carefully work the end cap off the hopper. The end cap contains a set of gears, and the drive gear for the developer roller will come loose. Be careful not to lose the gear! Also on this end cap is a spring loaded arm assembly. This arm we believe locks the cartridge in place once the tray is inserted and the cover closed. See Figures 28, 29 and 30.

[10] Remove the idle gear as shown. Leave the other gear in place as it will not come off, and is very difficult to match back up with the toner auger shaft inside the hopper. See Figure 31.

[11] Remove the screw on the contact side end cap. Remove the end cap. See Figure 32.

[12] Slide the developer roller over and remove. See Figure 33.

[13] Remove the two screws and doctor blade. See Figure 34.

[14] At this point, while tight, you can clean and fill the hopper with 2025 toner. See Figure 35.

NOTE: HP/Canon created a bit of a block for us here. The clear bushing located on the right side of the hopper. (See Figure 36) is glued in. The opposite side bushing is integral to the hopper. If you wish to install a seal, change the feed roller, or just have better access to the hopper, the feed roller must be pulled over to one side compressing the foam. First remove the two white felt seals. See Figure 37.

 

At this point we do not know if this will damage the roller or affect the printing at all. So far in our tests it has not, but it’s too early to say for sure. See Figures 38 and 39.

[15] If you have not already done so, fill the hopper with HP CLJ CP2025 toner and install the feed roller. See Figure 40 and 41.

[16] Install the two white felt seals on the feed roller shaft. See Figure 42.

[17] Clean the doctor blade foam seal. Install the doctor blade and two screws. See Figures 43 and 44.

[18] Clean the contact on the contact end cap with a cotton swab and alcohol. Replace the conductive grease with fresh grease. Remember, more is not better with this grease. See Figure 45.

[19] Replace the contact end cap and screw. See Figure 46.

[20] Install the developer roller. See Figure 47.

[21] Replace the idle gear as shown. See Figure 48.

[22] Install the gear end cap and screws. Turn the developer roller so it mates properly with the drive gear. Make sure the spring arm works! See Figures 49, 50 and 51.

[23] Coat the drum with you preferred lubricant and install the drum in the waste hopper. See Figure 52.

[24] Hold the two halves together. Align the spring on one side and the spring loaded arm on the other. See Figures 53 and 54.

[25] Install the outer gear side and cap and two screws. See Figure 55.

[26] Install the remaining outer end cap on the contact side of the cartridge and two screws. See Figure 56.

[27] Install the drum cover on to the cartridge. Spread the two halves apart slightly so it fits properly. See Figures 57 and 58.

[28] Remove the chip by cutting the plastic off the edges of both side of the chip. See Figure 59.

[29] Remove and replace the chip. See Figure 60.

[30] If the new replacement chip is loose in the slot. Close off the top edges with small amounts of hot glue.

Taking Test Prints

Press OK to open the menus

Press the left or right arrow until "REPORTS” appears on the display. Press OK.

Press the left or right arrow until the report you want is shown. Press OK.

There are multiple reports to choose from: Demo page, Menu, Configuration, Supplies status, Font, Color usage, service and more are available

Press X to exit the menus.

Repetitive Defect Chart

ITB Drive roller — 78.0mm
OPC Drum — 75.0mm
Fuser Pressure Roller — 63.0mm
Transfer Rollers — 58.0mm
Fuser Sleeve — 58.0mm
Registration Roller — 44.0mm
Primary Charge Roller — 38.0mm
Developer Roller Sleeve — 22.0mm

Some of the more common Printer Error Messages

Most of the error messages are in plain English, but some are numeric only. We have listed the more common ones here. Most of the internal errors listed in the service manual just state something like "Internal hardware error.” They are not very helpful.

10.000X Supply Error: Chip cannot be read or cartridge is not properly installed

10.0000 — Black Chip error
10.0001 — Cyan Chip error
10.0002 — Magenta Chip error
10.0003 — Yellow Chip error

10.100x Supply Error: Cartridge/Chip is missing

10.1000 — Black cartridge/chip missing
10.1001 — Cyan cartridge/chip missing
10.1002 — Magenta cartridge/chip missing
10.1003 — Yellow cartridge/chip missing

51.XX Printer Error

Internal hardware error. (This can be caused if a surge protector is being used. HP recommends removing it and plugging directly into the wall in the case.

Calibrate Now

Sometimes the only way to fix print quality issues is to force a calibration.

Open the HP Color LaserJet Toolbox
Click the device settings folder, then click on the Print Quality page
In the area for color calibration, select Calibrate Now.
Click Apply to start the process.

Print Density Settings

These functions are only available through the Tool Box.

There are actually multiple sub settings that can be set under density. As you can see, these settings can get a little intense and complicated.

Contrasts: Contrast is the range of difference between light (Highlight) and dark (Shadow) colors. To increase the overall range between light and dark colors, increase the Contrasts setting.

Highlights: Highlights are colors that are nearly white. To darken highlight colors, increase the Highlights setting. This adjustment does not affect midtone or shadow colors.

Midtones: Midtones are colors that are halfway between a white and solid density. To darken midtone colors, increase the midtone setting. This adjustment does not affect highlight or shadow colors.

Shadows: Shadows are colors that are nearly a solid density. To darken shadow colors, increase the shadows setting. This adjustment does not affect highlight or midtone colors.