MP4000 Gray Backgoround on Copies

[Vioksrall]

It's already 10,000 copies after we replaced PM parts of this MP 4000. Now our customer observed that after copying 5 copies,gray background covering the whole sheet of the paper appears. I tried to clean the PCU and changed charge roller but still no to avail. Does anyone had experienced the same problem as this? Thanks.

[dawn]

Hope it will help you.
RTB No. RD009024 : Dirty Background Image
Question Dirty background image sometimes appears under certain conditions which mentioned in "Cause". Answer CAUSE

The TC (toner concentration) in the development unit is too high.
The factors of this condition are as follows:
- It may occur easier in the low humidity and low temperature conditions.
- It may occur easier when the print volume is high.
- It may occur easier when a lot of one-to-one prints are made.
- It may occur easier when a lot of paper dust is contained in the recycled toner.
- It may occur easier when the print with high image coverage.
The process that the problem occurs is as follows:
TC becomes high caused by the above factors => Accelerates the "Toner Filming" on the development roller => Toner over toning, dirty background.
TEMPORARY SOLUTION

To reduce the TC in the development unit and generation time of this problem to be delayed, change the development bias as follows:
- Increase the development bias for ID sensor pattern to reduce the toner concentration.
- Increase the development bias to increase the image density.
REQUIRED ACTION IN THE FIELD

When this issue occurs, please perform the following procedure.
1. Before changing the development bias,
- Replace the Developer
- Clean the development roller surface
- Clean the recycled toner pathway in the PCU. (Refer to the following procedure for more detail)

2. Make the following SP mode changes:
- SP2201-01 (Development Bias): From 550 to 660
- SP2201-02 (Development Bias for ID sensor pattern): From 400 to 500
(Remarks)

1. The above procedure is not final solution. Even if you perform the temporary solution, generation time of this problem to be delayed, but this problem may occur under the following conditions.

1) The conditions listed above, which are mentioned in the Limitation List for Al-C1 as follows.
- Low temperature (10 degrees C) and low humidity (15%)
- Printing volume that exceeds the maximum CV of 30k/month

Note: This tends to occur often when the machine is used for the first time in the morning, following a day of high-volume printing.

2) Conditions related to user operations (when two or more of the conditions as explained "Cause " are met simultaneously)

[Cleaning Procedure for the recycled toner pathway in the PCU]
These procedures are for cleaning out the recycled toner (location shown in the following photo).

1. Remove 4 screws

2. Slide the developer tank about 5mm then remove the stopper.

3. Remove the plate A which is fixed by tape
4. Remove the Spring A
5. Remove 4 screws

6. Remove upper cover then clean out the recycle toner using a vacuum cleaner.


7. Re-attach all removed parts.
[IMPORTANT]
1) You should install the green lever together with the upper cover.
2) It is easier to install spring A if you use a small screw driver.


FINAL SOLUTION

We are still investigating the final solution and we will let you know the results as soon as it is fixed.
Could you please give as more time to provide with the final solution, because we should review the entire copy process. In the meantime, please perform the temporary solution as shown above if this problem occur.

[teebee1234]

The most important steps are to replace the developer mix and clean or replace the mag roll itself (it will be filmed over).

[aabarnes1]

Is the mag roller clean? Sometimes you need to run off over a hundred copies to 'clear' this problem after you have cleaned the pcdu.Did you change the dev? If so did you clean out all the old toner and dev from the pcu and cover the chute when initialising the dev.

[wfinn]

This is what I do for the MP4000 and MP4001 series copiers. This seems to work well but it doesn’t prevent the problem completely. The problem is with the toner which Ricoh has stated but this seems to be very effective at preventing the overtoning.

The first step usually is to vacuum the pig out. Separate the development units, pull the drum and clean it out as best as you can. Try and get out as much toner as possible. On top of the unit there is a toner recycling auger that needs to be cleaned as well.


Recycling Removed.jpg



Take the screws out on top and carefully (the tabs break easily) remove the top of the drum unit and clean inside.

Verify that the development unit is the new unit (old one has one big vent hole and new ones have three vent holes and extra grounding tabs) and then try and clean the mag rollers. If they cannot easily be cleaned then the whole unit must be replaced because scotch bright cannot be used on these. It will clean it but the coating will be removed and they will cover with toner very quickly. Also you are not able to order just the mag rollers for this model due to factory gapping that cannot be done in the field. There is a part number but if you place an order for it, Ricoh will cancel the order and send you a message stating the same thing I just did. I know because I tried it.

Ricoh passed out a bulletin stating that it’s better to take out the second cleaning blade due to drum life, they also don’t include them in the kits or with new machines now. You don’t have to do this but I always add the second cleaning blade back into these machines, because in my tests the machine ran cleaner with the blade in.

Now that you have a new or clean unit pour in the new developer, place a piece of paper over the entrance hole to the development unit and reattach the development unit to the drum unit.


Paper On Devo.jpg
Make sure the paper does not block the grounding tab that is beside the entrance hole.

In SP modes there are two voltages Ricoh states needs to be changed. They are 2201-001 and 2201-002. Increase both of these by 100.

Voltages.jpgVoltages (1).jpg
There is a method for testing drum ground on these machines but the ones that I did test failed badly so I have been adding this extra grounding strap to all of the machines. On the back you can easily see the drum shaft and can easily attach the grounding strap from the motor shown to the drum shaft.The drum grounding strap shown in the picture was discontinued and deleted by Ricoh but you can easily find a substitute. This was actually a strap from an older machine that had a drum grounding problem as well. Just a slight modification and it helped solve overtoning on this machine.


Bracket Installed.jpg
Apply a conductive grease to the shaft before adding the strap to help better ground the shaft.

After this has been completed then reinstall the PCDU unit and make 13 skyshots with a one inch lead edge to prevent jams in the fuser. This will help drop the density down in the new developer.



I usually have the machine in SP modes throughout the whole process to prevent any problems with print jobs or faxes trying to come through. After you run your skyshots initialize the developer then the run you ID sensor pattern. If the machine codes don’t panic, just open the front door, reboot and finish where you left off. It has only happened to me one time out of all the machines I have done.

The work is now done, remove the paper you installed between the drum unit and development unit (careful because there is usually toner on it) and run an SMC report for a test print.


Another thing to remember on this machine is every PM you have to change the Developer.


This method has proven very effective and I spent a few months working through multiple bulletins and tips before I came up with the right combination of fixes. Give it a try, it hasn't failed me yet and I have done this on several machines over the past year and a half.

[spree]

Hello, please read the text down. Do you thing I have the same problem and I can use this solution for my problem?
Please read:

I have trouble with Ricoh Aficio MP4000.
I changed20180828_222254.jpg20180828_143842.jpg:
- OPC drum
- OPC drum blade
- pick-off pawls
- transfer belt
- transfer belt blade
- charge roller apply
- brush roller
- developer
- developing filters

1.) Make developer initialization (ID sensor initial setting) SP3001-2,
2.) Grayscale setting SP2810-1
3.) After replacing the charge roller and cleaning roller, I checked the value of SP2001-001 and set SP2001-001 to "1500".
4.) Set the developer lot number (from developer package) - SP2801
5.) * see the mark

The printed black was perfect.
BUT after 25.000 copies: printed black was not so perfect - see picture.
What did I do?
I tried Development bias adjustment SP2201-1, than SP2001-1, SP2005 - nothing happened - the printed black was not so perfect.
Than I tried Forced Toner Supply - SP2207.
The black was perfect, but many black shadows at the papers. I make 80 copies and the black shadows gone away - perfect.
But I tried to make some black copies (when you open ADF, and scanner scanned only clean glass) - 5 copies, or 3 copies, but only one scanning of the image (clean glass)!
First copy was not so good, but the others were in poor quality and worst as first copy - see picture attached.
I tried to adjust values for TD sensor manualy SP2802-1 - but nothing happened.


Do you have some idea what is wrong, or why this happened, or what to do, change...?
Recapitulation: (I changed many parts in PCDU - drum, developer, ...), but after 25.000 pages the black is not in good condition (preventive maintenance for drum, developer, ... is 160.000 pages!). After forced toner supply black is better, but problems with copies: first copy not so good, other copies bad.

Now customer will test it and we will see if it appears again (black not so perfect, after xxx copies...).


*Probably I miss 2805-1 - could be this the problem???

[slimslob]

Go away grave robber. This thread has been dead and buried for 7 years.

[davel]

First thing clean laser shield glass then clean dev roller shined, replace dev run SP 2801 dev initialise.

[spree]

Thank you for answers.
Phil B.: The new drum life was in some cases only 20.000 pages? The new spare part - drum was faulty after 20.000 pages?
No I did not clean whole insides.
Davel: I clean laser shield glass, but clean developer roller was as new, when I looked at it.

Do you think, when I buy new whole developing unit, replace developer, than buy new PCU unit: replace new drum it will be helpfull and it will keep fine 160.000 pages (as PM say)? Or there can be still the problem with drum, that some drums stand only 20.000 pages (shit product)?

[davel]

Buy SP 8200 maintenance kit 402960. Stay away from non genuine parts.