big problem of Konica Minolta C6500

[shawn Xia]

the test pattern is 53,density setting is 80.the copy is showed as belowtest1.jpg

see the outside,it is different with other area.it is hard to express，the outside of the copy is like swept by something.
I change the drum,developer,developing unit,charging unit,transfer unit and clean the black laser unit,no change!

any suggestion?

[albasoul06]

change Interface cable

The internal test patterns are stored on the Image Process Board

Try depleting toner, if needed, from the suspected unit by running halftones of test pattern 53, density of 255 (leaving toner hopper unit open so it will not add toner). Check if the TCR value rises, achieving a value of 130.

[Stirton.M]

It is really hard to tell what the issue you are having with that image. Aside from some slight uneven density, I do not see what you refer to as swept...

Outside I assume you mean front side of the machine, inside is the backside of the machine?

Is that the whole page, or just a section of it? And is the blemish seen on the right side a part of the problem?

Some other things to check, since you eliminated pretty much the entire process unit.

Clean the slit glass assemblies for each colour.

The second transfer roller, inspect the unit. If you did a PM, did you replace the roller and discharge/neutralizing unit? Further to the 2nd transfer roller, the copper grounding tab on the front side of the roller, ensure that the little button that makes contact with the steel shaft of the 2nd transfer roller is clean and oxidize free. Use a little emery paper if needed.

Also on the 2nd transfer frame, a black mylar can be seen on the paper guide just before the roller, running the length of that guide. If the the mylar is damaged, that is, it is splitting along the middle where it meets the metal of the guide, it should be replaced. In severe situations, it can brush against the underside of the transfer belt and smudge the image before it is transferred to the paper stock.

It is possible there is an issue with the first transfer roller for black, though I doubt this. Inspect anyway, just in case.

Inspect the fusing unit for problems. Obviously of course, if the other colours are fine, the fusing unit is not the issue. But then again...

And lastly, the colour registration assembly, inspect it. Pay attention to the front and rear sensor windows...sometimes toner dust can get inside these and cloud up the plastic window. This is likely not where your problem is, but as I said, from the image, it is hard to see what your actual problem as described is.

[shawn Xia]

to albasoul06:thank you for your post. I think Interface cable is ok.because the problem is obvious when I print 53 test pattern.So I think there is some problems in the engine not DFE or Interface Cable.

I replace the black developer unit with Cyan(from the same machine and the cyan color hasn't problem),no change.It means that the developer unit and developer is no problem.

[shawn Xia]

To Stirton.M: You are warmhearted,and thank you so much for your long post. I think I have not expressed the problem clearly and the scaning image is not clearly too.but please check it carefully,you will find the difference with the bottom and middle part of the copy.

I print 53 test pattern by A3 PAPER.the scaning image is just the left part of the A3 paper.Do you notice the bottom of the copy is not as smooth as the other part(especially the middle part),it problem just like lacking of developer.Have you seen the problem of lacking of developer?the image is not solid.

the 1st BTR of black is ok.because I change the whole transfer belt unit.No change
Actually,I print 58 test pattern and desity setting is 80,only the black has the problem,cyan and magenta is ok.

[mrwho]

There was some old problem related to uneven density related to the drum positioning - The print would either be lighter on one side and darker on the other, or lighter/darker in the middle in relation to the extremities. Is that what you're talking about?

Check the following attachment - it is quite old and I ignore if there's a better solution nowadays, but it's here nevertheless.

[shawn Xia]

53pattern_p.jpg53pattern_h.jpg

thank you mrwho. I understand what you say,and do it according to your post. but the result is not santisfy.
see the change of the front of the copy.
I havn't the writing unit ,so the test hasn't done yet.

[shawn Xia]

the 52 pattern is like below52pattern.jpg

[HORSE]

Check the Corona wire in the Charge unit is sitting correctly.

[shawn Xia]

I hop it is,but it's not.

[inutelkamo]

Re: big problem of Konica Minolta C6500

Hey men...

what is the status of this problem?

check mine.. i guess i have the same problem.. but mine is a bit different, check the files.. dont mind the dirt on the scanners flatbed.
paper is kromkote 210gsm, test pattern 53 at 155 value.the left side of the image is the leading edge and the left side is the trailing edge.
Maybe if you guys ever encounter this, it would be a great help..

btw, black has new dev unit, dev, drum and charge, new intermediate Unit, new 2nd transfer roller.

[DigiMan]

Re: big problem of Konica Minolta C6500

the test pattern is 53,density setting is 80.the copy is showed as below[ATTACH=CONFIG]7504[/ATTACH]

see the outside,it is different with other area.it is hard to express，the outside of the copy is like swept by something.
I change the drum,developer,developing unit,charging unit,transfer unit and clean the black laser unit,no change!

any suggestion?

Did you check the lower transfer roller on the transfer belt?
Had a similar problem once where the bearing on the inside wasn't spinning correctly and was causing a similar problem.
Plus if i remember correctly theres a screw there in which you can adjust his pressure on front to back(could be mistaken about this though).

EDIT:Just saw you said you changed the whole transfer belt unit?If so scrap my post.

[Ahnou123]

Re: big problem of Konica Minolta C6500

just follow mrwho. try to adjust the distant between drum cartridge and charge unit. Will solve ur problem

[methogod]

Re: big problem of Konica Minolta C6500

did you close the flip tab on the black developer unit after adding new developer at PM?...
did you take the red screws out of the black drum?....

i take it that all other colors but black are printing fine, that eliminates just about everything else....