bizhub 1051 garbage on paper, buggy test pattern

[emato]

Hi!

Please, look at the examples of printed pages, it has chunk of toner, that i can remove with hands. While printing this garbage spread to ADU and transfer belt very rapidly. When I stop machine during printing, I can see this chunk on the surface of drum.

Also, on test pattern #3 solid rectangles has rugged upper side and bold lower side. In normal machines rectangles are solid.

I replace charge unit, developer unit with developer, discharge wire, cleaning unit(to ensure), drum. But nothing helps, for more than a day.

Also this machine always has problem with transfer cleaning unit, it stuck full of toner, I replace it with another one, it works for week maybe and then repeat.

I appreciate any ideas. Thank you.
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[Luther]

That looks like either bad toner or non OEM toner contaminating the dv, i would clean out the toner and start fresh with a new oem toner

[emato]

That looks like either bad toner or non OEM toner contaminating the dv, i would clean out the toner and start fresh with a new oem toner

We use only Konika Minolta original toner developer always. However I changed it twice. With new developer it works for a day or less. Until automatic adjust

[emato]

up

[emato]

I forget to mention that machine has 26 million of printed pages :D

[emato]

please help someone. maybe post this on konica minolta solutions?

[kalindd]

From what I see, there might be few different problems.
Looking at the second picture I would tell that the charge is way too high or the bias is improper. Both of those things will cause issues like yours.
On the fourth picture I see huge density shift. How about checking if the drum carriage is parallel/straight. Does the charge corona sits properly?
Maybe writing unit needs to cleaned. Maybe drum potential sensor has failed and needs to replaced. You may have bad drum ground.

Check those things and see if something comes up.

[emato]

From what I see, there might be few different problems.
Looking at the second picture I would tell that the charge is way too high or the bias is improper. Both of those things will cause issues like yours.
On the fourth picture I see huge density shift. How about checking if the drum carriage is parallel/straight. Does the charge corona sits properly?
Maybe writing unit needs to cleaned. Maybe drum potential sensor has failed and needs to replaced. You may have bad drum ground.

Check those things and see if something comes up.

After this message i desided to do auto drum potential adj. And it never ends with success. It shows error 2, error 3, or machine stop with sc-2810 or sc-2811 (dps fail). I replace dps from 920 biz, no changes. After that i check wiring from sensor to PRCB, and all ICP on PRCBand it is ok. After that i change charge unit. No result. I can't understand why test fails. Also print images is very poor, and poor on drum surface too. I also set new drum. And developer unit has blank band on surface(without developer)

[Synaux]

After this message i desided to do auto drum potential adj. And it never ends with success. It shows error 2, error 3, or machine stop with sc-2810 or sc-2811 (dps fail). I replace dps from 920 biz, no changes. After that i check wiring from sensor to PRCB, and all ICP on PRCBand it is ok. After that i change charge unit. No result. I can't understand why test fails. Also print images is very poor, and poor on drum surface too. I also set new drum. And developer unit has blank band on surface(without developer)

Have you tried replacing the sensor behind the drum?

[allan]

After this message i desided to do auto drum potential adj. And it never ends with success. It shows error 2, error 3, or machine stop with sc-2810 or sc-2811 (dps fail). I replace dps from 920 biz, no changes. After that i check wiring from sensor to PRCB, and all ICP on PRCBand it is ok. After that i change charge unit. No result. I can't understand why test fails. Also print images is very poor, and poor on drum surface too. I also set new drum. And developer unit has blank band on surface(without developer)



Did you say you changed the dev tank? That line on the mag roller is a shifted magnet angle.

[kalindd]

After this message i desided to do auto drum potential adj. And it never ends with success. It shows error 2, error 3, or machine stop with sc-2810 or sc-2811 (dps fail). I replace dps from 920 biz, no changes. After that i check wiring from sensor to PRCB, and all ICP on PRCBand it is ok. After that i change charge unit. No result. I can't understand why test fails. Also print images is very poor, and poor on drum surface too. I also set new drum. And developer unit has blank band on surface(without developer)

To me the dev unit looks ok. Like Allan wrote that band is normal.


I don't think that drum pot. sensors are the same for 920 and 1051 (I'm sure that are not). Did you swap only the sensors?
When you replace the drum pot. sensor it comes with a small board, both are matched together.
To check whether you have failed drum pot. sensor you can disable it. Go into service mode and change DIPSW 6-7 from 0 to 1. Then go back to Process adjustment, press Recall Standard data and press Factory initial data.
Go to High voltage adjustment and run Auto high voltage adjustment. In most cases it will pass successfully.
If it passes go back one step and get into Drum peculiarity adjustment, run Automatic drum potential, Auto maximum density adj., Auto dot diameter adj. and then Cartridge set mode.
Check the image.

You did not mention anything about the huge density unevenness on the page. That might be the real problem

Next thing I would guess is maybe the HVPS or write unit are failing.
But of course that is very hard to tell. Sometimes we all face the situation when we need start replacing suspected parts one by one.

Good luck and let us know the results.

[allan]

To me the dev unit looks ok. Like Allan wrote that band is normal.


I don't think that drum pot. sensors are the same for 920 and 1051 (I'm sure that are not). Did you swap only the sensors?
When you replace the drum pot. sensor it comes with a small board, both are matched together.
To check whether you have failed drum pot. sensor you can disable it. Go into service mode and change DIPSW 6-7 from 0 to 1. Then go back to Process adjustment, press Recall Standard data and press Factory initial data.
Go to High voltage adjustment and run Auto high voltage adjustment. In most cases it will pass successfully.
If it passes go back one step and get into Drum peculiarity adjustment, run Automatic drum potential, Auto maximum density adj., Auto dot diameter adj. and then Cartridge set mode.
Check the image.

You did not mention anything about the huge density unevenness on the page. That might be the real problem

Next thing I would guess is maybe the HVPS or write unit are failing.
But of course that is very hard to tell. Sometimes we all face the situation when we need start replacing suspected parts one by one.

Good luck and let us know the results.

No shifted magnet angle is no good that band should not be there. The erratic magnetic brush could cause all of that problems. There is smear marks on the trailing edge of the letters. Could very well be cause by that problem.

Is the line there if you rotate the developer unit by hand?

The drum potential sensor should never be cleaned or vacuumed.
The adjustment could fail because of a bad DPS or that the drum is not getting enough charge.

kalindd mentioned there is probably another problem that is causing the uneven density like a dirty or shot charge unit.

Bad drum earth?.

Follow kalindd's advise to disable the DPS i have never done that.

[kalindd]

My bad Allan, I misunderstood you.

I haven't seen 1051's dev tank for about year and a half and I can't confirm how the mag should look like with developer brush on it.
But yes if the magnet angle is shifted you are in a lot of trouble.

The guy wrote on his first post that he replaced the dev tank and he can confirm if that's true.

Another thing that comes into my mind is, how is distance between drum and dev unit?

[emato]

thanks to all of you. I changed dps(from bizhub 1050), and adjust complete successfully, also all test pass well. and it seems that troble is solved, i print maybe 5000 prints and all is ok.