To achieve the advantages of a single-pass system, each toner cartridge has its own dedicated imaging system – drum, charge roller and waste bin. This presents many advantages to the remanufacturing industry; however, the OEM has placed some hurdles that have to be overcome.

Toner.

1) Replacement drum.

2) Wiper blade.

3) Doctor blade.

4) PCR.

5) Magnetic roller sleeve.

6) Conductive grease.

1) Toner-approved vacuum.

2) 3-mm (1/8 inch) flat-head screwdriver.

3) Phillips-head screwdriver.

4) Needle-nose pliers.

5) Drill with 4-mm (11/64-inch) bit.

6) Side-cutting pliers.

The first hurdle is noticed when attempting to dismantle the cartridge. As with the HP 1200 cartridge, the endpins cannot be removed without making some minor alterations to the cartridge. The following instructions are a guide for dismantling the cartridge without having to purchase specially designed tools for removing the pin.

It should be noted at this point that, apart from the label and toner, each of the four cartridges appears to be identical. See Figure 1. Even the black cartridge uses a rubber-type developer roller, as do the color cartridges. Therefore the following instructions apply to all four cartridges.

1) Locate the slots at both ends of the cartridge as highlighted in Figure 2.

Drill a 4-millimeter (11/64-inch) diameter hole through each slot angled towards the pin. The drill will not go further than the depth of the pin. See Figures 3 and 4.

2) Using a flat-head screwdriver with a 3-millimeter (1/8-inch) wide tip, insert the screwdriver into the hole with the flat portion of the tip facing the pin. See Figure 5.

3) Push the screwdriver in behind the pin and turn in either direction. This action will push the pin out as illustrated in Figures 6 and 7.

4) Grip the pin head with a pair of side-cutting pliers and maneuver the pin out. See Figures 8 and 9.

5) Using a flat-head screwdriver, unclip one end of the tension spring. Simply lift the spring up and over the anchoring tag. See Figures 10 and 11.

6) Lift the toner hopper portion of the cartridge away from the waste bin portion. See Figures 12 and 13.

Testing and research indicates that all components can be reused for a number of cycles if qualified. Lab research indicates that the soft chemical toners cause much less wear on components than iron-oxide-based toners.

1) Using a Phillips screwdriver, unscrew the screws highlighted in Figures 14 and 15. The handles can then be removed from their positions.

The handle at the drive end of the cartridge will remain on the drum shaft.

2) Remove the star-lock clip by wedging it off the shaft with a flat-head screwdriver as illustrated in Figure 16. Then remove the washer. See Figure 17.

3) Wedge a flat-head screwdriver down the left side of the drum as illustrated in Figure 18.

4) Tilt the screwdriver to force the drum sideways, as illustrated in Figure 19. This will also push the shaft out the right-hand end.

5) The extended shaft length at the right-hand end will allow you to grip the drive coupler and pull the shaft out. See Figures 20 and 21.

6) Carefully maneuver the left-hand end of the drum upward and lift the drum away from the cartridge as illustrated in Figure 22. If the drum is reusable, store it correctly.

7) Remove the PCR and clean with a damp cloth. Allow it to dry before installing.

8) Empty the waste bin and vacuum or blow the outer shell clean.

If the wiper blade has been qualified for reuse then there is no need to remove it.

1) Locate the Phillips screw highlighted in Figure 23. Unscrew these screws and remove the end cap.

2) Use a flat-head screwdriver to press in and unclip the supporting clip highlighted in Figure 24. It will be necessary to pull the cap away while pressing the clip in.

3) Carefully remove the filling plug, as illustrated in Figure 25. Apply a vacuum hose over the plug and turn the developer roller in the correct direction (away from the doctor blade). This will remove all remaining toner and clean out the toner hopper. Fill with new toner.

4) If you wish to remove the end bracket for the purpose of seal application, then unscrew the two screws highlighted in Figure 26. If you do not seal the toner hopper, then be sure to blow all toner off the developer roller with an air gun after post-testing.

5) Reinstall the end cap, ensuring that the contact spring inserts into the rectangular bush end hole, as illustrated in Figure 27.

If the developer roller needs to be removed for cleaning or replacement purposes, then follow the instructions in this section.

1) Unscrew the two Phillips screws highlighted in Figure 28. This will allow access to the end bracket. It will be necessary to first remove the gears, as illustrated in Figure 29.

2) Remove the gears in order from one to six, as seen in Figure 30. Gear six will need to be carefully unclipped.

3) Unscrew the two Phillips screws highlighted in Figure 31. Then pull the bracket away sideways, as illustrated in Figure 32.

4) Figure 33 shows the three rollers of the HP 4600 developing system. Notice the additional regulating roller.

• First remove the regulating roller by pulling it sideways. See Figure 34.

• Then, remove the developer roller by pulling it sideways. See Figure 35.

Reassembly of the Developing System

Assemble the hopper using the exact opposite procedure from dismantling. Screw the end bracket back in place.

When applying the gear illustrated in Figure 36, ensure that the locking slot matches up with the key of the paddle drive shaft.

Install the gears in order from one to six, as highlighted in Figure 37. Check that the gears are the correct way.

1) The drum must be installed the correct way. Figure 38 highlights the keyed end of the drum that must be inserted into the right-hand end of the cartridge.

2) Carefully insert the drum shaft back into position as illustrated in Figure 39. Hold the left-hand end bearing in place while inserting the shaft. See Figure 40. The shaft will need to be turned slightly to engage the shaft-locking pin into the drum key slot.

3) Apply the washer, and then press the star-lock clip back over the shaft. See Figures 41 and 42. Check that each end of the shaft is sitting in place correctly.

4) Assemble the two halves together. It is important to raise the drum shutter upward and lower the toner hopper downward under the shutter to prevent damaging the shutter blade. See Figure 43.

• Insert the two endpins and press fully in place.

• Re-install the tension spring that was removed in Figure 11.

• Install and screw into place the two cartridge handles that were removed in Figures 14 and 15.

The cartridge is now ready for post-testing. Before packaging don’t forget to blow off any toner from the developer roller with clean air. To gain access to the developer roller, simply hold the drum shutter open, and squeeze the two halves of the cartridge together from the back. This will open a gap above the drum to apply air to the developer roller.  This completes the recharging!