• First introduced in March 2011, the HP LaserJet Enterprise 600/MFP 4555 engine is a 43-62ppm (depending on model), 1200 dpi multi-function engine. The new CE390A and CE390X cartridges are rated for 10,000 and 24,000 pages respectively. As with all mono black HP cartridges to date the chip is mainly controlling the toner low functions and of course the HP/Non HP cartridge message.
  
  HP initially released the MFP machines first, then a few months later the Enterprise 600 series was released.
  
  These are nice cartridges to do in that there are no plastic rivets to cut or drill, All the screws are the same size, and no glue type seals are used anywhere inside.
  
  The current machines that use these new cartridges are as follows:
  
  HP LaserJet Enterprise 600 M601n
  HP LaserJet Enterprise 600 M601dn
  HP LaserJet Enterprise 600 M602n
  HP LaserJet Enterprise 600 M602dn
  HP LaserJet Enterprise 600 M602x
  HP LaserJet Enterprise 600 M603n
  HP LaserJet Enterprise 600 M603dn
  HP LaserJet Enterprise 600 M603xh
  HP-LaserJet M4555h mfp
  HP-LaserJet M4555f mfp
  HP-LaserJet M4555fskm mfp
  
  These cartridges are also very profitable to make! The retail price for the CE390A is $238.50* and the CE390X is $398.56*
  
  *Pricing as of December 2011
  
  One very interesting note is that the printer uses the laser scanner unit to eliminate residual charges from the OPC drum. Here is what the service manual says on this: “The residual charge on the photosensitive drum surface is eliminated to avoid uneven image. The residual charge of the previous image is left on the drum surface after the transfer operation and this affects the following image formation. The product eliminates this residual charge by emitting a laser beam to the drum surface. The drum charge elimination is operated only during the last rotation period”.
  
  So basically after the wiper blade cleans the drum, the laser fires again at a different intensity to electrically clean the drum. The PCR is still charging the drum with both AC and DC signals so it is still cleaning the drum electrically too, but the laser is helping do this by eliminating most of the charges before the PCR fires. This is most likely needed because of the speed of the machine.(Up to 62ppm)

Figure 1

Figure 1 shows the shipping seals in place on a new OEM cartridge. The main seal separates the two halves of the cartridge relieving some of the pressure on the various spring loaded and foam assemblies.

Printer usage, as well as some common printer/cartridge problems will be covered at the end of this article.


Required Tools

1) Toner approved vacuum.
2) A small Common screwdriver
3) A Phillips head screwdriver
4) Needle Nose Pliers
5) Magnetic roller press

Supplies Needed

Polyester based toner; 1100g for the HY, 725g for the LY
Replacement drum
Wiper Blade
Doctor Blade
PCR
Magnetic roller sleeve
Conductive Grease
White lithium grease
Replacement chip

1) Place the cartridge with the toner hopper facing up and towards you. This will orient the cartridge for right and left sides.

2) Remove the five screws on the right side end cap. See Figure 2

Figure 2

3) Open the drum cover towards the back of the cartridge. Remove the right side metal bar by pressing it out of the small clip. See Figure 3

Figure 3

4) On the opposite side of the cartridge, carefully pry off the drum cover plastic arm. The spring will probably pop off, take care not to lose it. We will go over the installation at the end of this article. See Figure 4

Figure 4

5) Remove the metal bar from the left side, and remove the entire drum cover assembly. Make sure you put the spring in a safe place. See Figure 5

Figure 5

6) Remove the 5 screws from the left end cap. See Figure 6

Figure 6

7) Remove the right side end cap from the cartridge. Note that the gears do not come off the end cap. See Figure 7

Figure 7

8) Remove the left side end cap. Both halves will come apart easily. Be careful not to damage the drum or mag roller sleeve. See Figure 8

Figure 8

9) Remove the plastic drum bushing/gear train assembly and screw. See Figures 9 & 10

Figure 9

10) Remove the drum. Lift it up from the large gear side, pull over and remove. There is no need to remove the drum axle pin. If it is removed, there is a chance that the hole in the plastic wall that it seats in will become enlarged slightly allowing the axle and drum to move slightly. This will cause banding. See Figures 11 & 12

11) Remove the PCR. See Figure 13

Figure 13

12) Remove the two screws from the wiper blade. See Figure 14

Figure 14

13) Due to the high speed and page counts of these cartridges, we recommend that the wiper blades be replaced.

14) Note that there is not any type of sticky sealant on the wiper blade. There is just normal foam and felt seals under the blade. Remove the wiper blade from the cartridge, and clean out the waste toner. Be careful not to damage the spring coming out from the black PCR holder. See Figure 15

Figure 15

15) Clean the PCR with your standard PCR cleaner.

16) Clean the felt and foam seals under the wiper blade. Make sure they are not compressed or they may leak. See Figure 16

Figure 16

17) Install the wiper blade and two screws. Be careful not to damage the small contact that comes off the PCR spring on the black holder side. See Figure 17

Figure 17

18) Install the cleaned PCR. Place a small amount of conductive grease on the black PCR saddle. Remember, when using conductive grease, more is not better! Also place a small amount of white lithium grease on the white holder side. See Figure 18

Figure 18

19) Install the drum, drum bushing assembly and screw. Make sure the gears from the bushing assembly align with the drive gear on the hopper. See Figures 19 & 20

20) Place the waste chamber aside.

21) On the supply chamber, carefully pry off the Magnetic roller (MRS) cover, and remove. See Figure 21

Figure 21

22) Remove the MRS drive gear. See Figure 22

Figure 22

23) Note the location of the spring that sits between the MRS holder and the hopper. Remove the two screws, spring and the holder. See Figures 23 - 25

Figure 23

Figure 24

Figure 25

24) Remove the MRS assembly. The left (non-gear) bushings may come off with the roller. If they do not, remove them so they are not lost or damaged. See Figures 26 & 27

25) Lift up on the clear scraper covers and remove the two Dr. Blade screws. Remove the two scrapers and the doctor blade. See Figures 28 - 30

Figure 28

Figure 29

Figure 30

26) Remove the fill plug from the hopper. See Figure 31

Figure 31

27) Clean out all the remaining toner in the supply hopper.

28) Note the magnetic seals on the MRS and the DB sealing foam. Make sure both are clean. See Figure 32

Figure 32

29) There are two separate mixing blades in the toner hopper. The largest is on the bottom, with the smallest on the top. Each is driven by its own separate drive gear. See Figure 33

Figure 33

30) The upper mag roller section of the toner hopper “Floats” on a series of foam seals. The upper half can be removed from the hopper, but some of the seals will be destroyed. This may become necessary in order to seal the cartridge. We will keep you informed on the availability of a seal system and how to install it as our testing continues. The foam isolates the mag roller from the vibrations of the mixing augers, and allows smoother prints.

31) Clean the mag roller contacts, and replace the conductive grease. If the plating on the contact is worn they should be replaced or banding will most likely occur. See Figure 34

Figure 34

32) Install the doctor blade, be careful of the alignment pins. For now do NOT install the scrapers or screws. See Figure 35

Figure 35

33) Clean the mag. roller with a dedicated mag roller cleaner. On the left side of the mag roller there is a small hub that is keyed into the MRS holder. Align the hub with its slot and install the hub as well as the entire MRS assembly. See Figures 36 - 38

Figure 36

Figure 37

Figure 38

34) Install the two doctor blade scrapers and screws. The clear scraper covers must sit on top of the roller. Installing them now will lessen the chance of damaging them or getting any grease on them. See Figure 39

Figure 39

35) Install the holder and spring. Make sure that the spring is compressed so it fits into its slot. This is easily done with a small screwdriver as the holder is pressed in place. If you are having a hard time getting the holder in place, take a moment to look at the angles of the plastic holder. They have to align with the corresponding angles in the hopper for it to fit. Install the two screws. See Figures 40 - 42

Figure 40

Figure 41

Figure 42

36) Install the MRS drive gear. See Figure 43

Figure 43

37) Install the keyed MRS cover. Make sure that the keyed hole in the cover matches the keyed end of the magnet in the MRS assembly. Note that the post on the front or DB side is longer than the back post See Figures 44 & 45

Figure 44

Figure 45

38) Fill with appropriate amount of M4555 toner, replace the fill plug. See Figures 46 & 47

39) Install the left side end cap onto the toner hopper. It is easier to install the end cap on the supply hopper first, install one screw and slide the waste chamber into the end cap. Install another screw from the end cap into the waste hopper to hold it in place. See Figures 48 & 49

Figure 48

Figure 49

40) Install the right side end cap and 5 screws. See Figure 50

Figure 50

41) Install the remaining 3 screws on the left side end cap. See Figure 51

Figure 51

42) Install the metal bars from the drum cover on both sides of the cartridge. Place the bars in front of their slots and press in place with a small screwdriver. See Figure 52

Figure 52

43) Install the spring into the drum cover arm as shown. Pull the upper tail of the spring until it fits into the notch in the arm hub. See Figure 53

Figure 53

44) Install the arm onto the cartridge. Pull back all the way and release the spring from the notch so that the tail fits as shown. See Figure 54

Figure 54

45) Replace the chip on the top of the cartridge. Replacing this chip will enable the toner low functions of both the cartridge and the machine again. See Figure 55

Figure 55

46) Install the plastic separator seal. This seal keeps the two halves slightly separated relieving the pressure of the various foam and spring assemblies. See Figures 56 & 57

Figure 56

Figure 57

Repetitive defect chart:

OPC Drum: 94mm
Upper Fuser sleeve: 94mm
Lower Fuser pressure roller: 94mm
Cassette Feed and separation rollers: 79mm
Tray 1 Feed roller, separation roller: 79mm
Magnetic Roller Sleeve: 63mm
Tray one pickup roller: 63mm
Pre-registration roller: 50mm
Feed roller: 50mm
Transfer roller: 47mm
PCR: 37.7mm


Test pages from both the laser printers an MFP machines:

Running the Cleaning Page

From the HOME screen, touch the Device Maintenance button
Open the following menu’s:
Calibrate/Cleaning
Cleaning Page
Touch the Print button to run the page
This process can take a few minutes to complete


Running Test Pages

From the HOME screen, touch the Administration button
Open the following menu’s:
Reports
Configuration/Status pages
Choose the Configuration page, Administration Menu map, Current Settings page or Status page, your choice.
Touch the Print button to run the report


Printer Error Codes

There are literally hundreds of error codes listed in the service manual on these machines. I have listed just the more common cartridge and paper jam codes here.

10.XX.YY Supply Memory Error: An error has occurred in one or more of the printers supplies. HP again call the chip a “memory tag” and the machine cannot communicate with one of them.

10.XX.33 Used Supply in use. (Chip not changed)

10.XX.40 Genuine HP Supplies installed

10.XX.41 Unsupported Supply in use. (Wrong chip installed)

10.YY.35 Incompatible supply in use

Error 13.XX.YY: All the error 13 codes deal with paper jams or a door open. There will always be a text message under the number code tell you where the jam is. These messages are very specific.