Faded colors in different paper sections and white lines on Ricoh MPC3002

[milosbabic]

Hi guys,

I have problem with my Ricoh MPC3002, colors prints unequally on the paper and 2 white lines occurs in the lower section of the paper.
Here is the image of printed Full Dot Pattern on Vtref_Fixed for Black on 3.5V, and color test page that shows how black fade in upper paper section and CMY fade in lower paper section. On full color test page it shows that white lines occurs only on black transfer.

1. Faded black in upper section
2. White lines from black
3. Faded CMY in lower section

I've already tried cleaning all the drums, replacing toners, correcting the gamma for K (3H 6M 8S 10ID_Max), cleaned fusing unit, tried different Vtref Display Set for K in Vtref_Fixed mode, and nothing changed. Please help me find the solution.
20241227_171437_marked.jpg

[Leoculus]

Hi guys,

I have problem with my Ricoh MPC3002, colors prints unequally on the paper and 2 white lines occurs in the lower section of the paper.
Here is the image of printed Full Dot Pattern on Vtref_Fixed for Black on 3.5V, and color test page that shows how black fade in upper paper section and CMY fade in lower paper section. On full color test page it shows that white lines occurs only on black transfer.

1. Faded black in upper section
2. White lines from black
3. Faded CMY in lower section

I've already tried cleaning all the drums, replacing toners, correcting the gamma for K (3H 6M 8S 10ID_Max), cleaned fusing unit, tried different Vtref Display Set for K in Vtref_Fixed mode, and nothing changed. Please help me find the solution.

For the voids in the black it is either something on the laser slit glass or something on the doctor blade in the dev unit blocking ever supply of toner across the mag roller. Could try back spinning the black dev to dislodge the blockage but it may just get stuck in a different spot. the fading for the black could be also slit glass or dev unit or possibly a Transfer issue

For the colour pattern though you say upper/lower if the sheet is printed LEF it would look like it is the leading edge. To me it looks like a paper transfer issue. Used to see the plastic hinge pin break on the rear side for the transfer housing on the right side jam removal door. also there are guides on the machine side that help position the PTR properly against the ITB that will become damaged if the user forces the door closed after the PTR housing is damaged.

[slimslob]

White lines like those can be one of two things neither of which you have mentioned addressing. You either have a dirty doctor blade or a dirty shield glass.

[sandmanmac]

White lines like those can be one of two things neither of which you have mentioned addressing. You either have a dirty doctor blade or a dirty shield glass.

This is just about the most basic Image defect there is, and Tim's bang on that it's either or 1 of those 2 things
The service approach you've outlined is what I would relate to the old saying "can't see the forest for all of the trees" .

You replaced all 4 toner cartridges? They would NEVER be the cause of a defect like this - unless they were crappy compatibles, and actually the cause of the "toner rocks" that have likely developed in your dev unit; However replacing them will NEVER resolve the issue.

[Larhal]

Looks like toner rocks. Pull developer and check for voids. If so you will have to empty the developer and screen it to remove the rocks.

[Codex]

Hello

check the development units, this kind of problem happens if developer or dirt stucks under the doctor blade.try to clean it with a piece of paper , if you separate the Pcu and the development assy you can see this lines on the mag roller.

[milosbabic]

Thank you everyone! Lines in the lower section disappeared, BUT I've stuck with another problem.

I've cleaned development unit, disassembled, emptied out the toner, cleaned it with vacuum cleaner and put the old toner back. Also i've cleaned Drum and Pressure Transfer Roller in Fusing unit because I found toner rock on that roller. I think all of that helped with lower lines, but on the next test vertical lines appeared and as I tried more and more tests (40 pages) new horizontal white lines appeared too. Here is the image of Full Dot Pattern for All colors(black) on Vtref_Fixed and Display/Set on 4V for black color.

Do you know why this happened and what to do to get rid of this?
20241228_195246.jpg

[slimslob]

Thank you everyone! Lines in the lower section disappeared, BUT I've stuck with another problem.

I've cleaned development unit, disassembled, emptied out the toner, cleaned it with vacuum cleaner and put the old toner back.

Vacuuming seldom removes toner rocks from the doctor blade. Before emptying the development unit, you have to clean the doctor blade either with a business card or by turning the drive gear backwards 3 or 4 revolutions.

Also i've cleaned Drum and Pressure Transfer Roller in Fusing unit because I found toner rock on that roller. I think all of that helped with lower lines, but on the next test vertical lines appeared and as I tried more and more tests (40 pages) new horizontal white lines appeared too. Here is the image of Full Dot Pattern for All colors(black) on Vtref_Fixed and Display/Set on 4V for black color.

Do you know why this happened and what to do to get rid of this?
20241228_195246.jpg

Based on the spacing of the lines, I would say you have damaged the charge roller.

[planetrob]

When I do PM on a drum and dev unit, I tap on it do force stuck on "stones" to come out all the while having my vacuum sucking away. I get a rag in where I can. I focus on getting them as clean as possible. That said, what do you mean when you said you "...put the old toner back..." ? Did you save what came out of it and put it back? I would sort of think that would cause more problems that is worth in the bag on toner savings.

[milosbabic]

Based on the spacing of the lines, I would say you have damaged the charge roller.

Luckily you were wrong, charge roller (if you've thought of one in the drum unit) is okay.

I have no idea what was the problem, but one more detailed cleaning of development unit helped with those vertical lines. This time I disassembled dev unit completely, including doctor blade, cleaned it with vacuum and dry cotton and sifted the toner where I've found couple of clots.

I tested it again, printing full black dot pattern, but have found that one third of paper (upper section) was nearly white, then I guessed that there is shortage of toner in dev unit so added some. This helped, so just a very narrow upper section of paper left poorly covered in black. Also I noticed that there is fewer toner at one end (corresponds to the top section of the paper) of the magnetic roller in dev unit no matter how much toner I spill on it. White lines didn't appear on couple of tests, but then begin to appear, this time on half of the width of paper (center to the edge).

Is it possible that magnetic roller weakened and that this caused problem with faded colors and white lines as well?

[Luism]

Hello, how many copies / prints does the equipment, the developer and the cylinder have? Are you using original toner? The use of non-original toner, apart from bringing that type of problem that you have, will sooner or later break gears, bushings and toner feed worm screws, what is cheaper at first later turns out to be more expensive. I serve more than 25 equipment with original toner and they have been carrying more than 100kc WITHOUT ANY TYPE OF CLEANING. For your problem, the most advisable thing is to change the developer (it does not come alone, the complete development unit comes) and your problems will be over, which also incur costs of wasted tests, paper and time, which is the most valuable thing we have.