PDA

View Full Version : C6501 - Blurry Text (Misregistered)


Custom Search


resolute
04-14-2011, 07:19 PM
I am battling a problem that has persisted for over 2 months now. We have a misregistration that is causing blurry text and seems to be mostly in the magenta. For example if I try to print blue text (100/70/0/0) the text will be fine in some places on the sheet - but blurry in other places - sort of looks like a magenta drop shadow. I looks to be about 2 pixels off. The technicians have replaced lasers, belts but have made no progress in resolving the problem. They are thinking about changing the main image control board - but are trying to explore other options as this is a rather expensive part.

I am hoping that someone else has had this problem and found a solution. We have not changed stock in the 2 years that we have had the machine... and until 2 months ago, did not have this problem.

Any advise or suggestions greatly appreciated.

pinoyprinter
04-14-2011, 09:02 PM
pls interchange the transfer rollers (CMY) inside transfer belt. if not try to replace color registration unit, and if not try firmware update.

empiru
04-18-2011, 05:45 PM
After conducting the Auto Color Registration Adjustment, what kind of values do you get for Magenta, in that Table?
It is possible, that the Transfer Belt is not installed correctly. Be careful: on the bottom of the transfer belt, there is a roller with a white plastic guide on each end. The Belt must fit almost perfectly into those guides.
I read that you have changed the belt, but it can be possible that it was installed the wrong way several times.
If this is not the case, I suggest you replace the Color Registration Assy - like pinoprinter said. It is located to the left of the Transfer Belt, as it is mounted in the machine and has 3 sensors that determine wether the colors are aligned or not.
I hope this helps!

seniortech
04-18-2011, 06:42 PM
After running Auto Color registration did you run the Manual color Registration adjustment?

jhbtech
04-18-2011, 07:38 PM
I have had the same problem but mine also shows a bit of yellow as well.i have changed laser units,transfer belt unit,color reg unit,and reg roller unit.my problem started a year ago and is most prevelent on 300gsm.if u have any solutions please post on this site.

empiru
04-18-2011, 09:11 PM
Ok, excuse me if I'm going to ask an obvious and stupid question... but... did you run all the adjustments in the manual when you changed a part?
Again, I know this is, in the copier world, like common sense... but did you?

jhbtech
04-18-2011, 09:26 PM
Yes I have.I get 000.0 values when I do auto color reg.I hve gone further by changing the pulse disc on tranfer belt drive and also swopped drum drive units but I still have a solution

empiru
04-18-2011, 10:12 PM
Ok, that's obviously a BIG problem - I've never seen a C6500 do that... This is very interesting for me, so I'll "dig" a little deeper and try to help you out.
I like them challenges :D

resolute
04-29-2011, 02:58 PM
A asked the tech about a manual color registration adjustment. - and got told it doesn't work. So they only do the auto color adjust. Can u provide me the instructions on how to do the manual adjust... Thanks

empiru
04-30-2011, 01:01 PM
Ok, that's a tough one. I mean, I provide service for 3 years now (I'm not saying it's a lot of time, I'm just trying to make a point); after my first year, I did a Manual Color Registration on a Bizhub Pro C500. It took me about 1 and a half hours and my result? I managed to completly "destroy" the machine. A far more experienced technician came the other day and spent about 4-5 hours to fix it...

So, please don't get me wrong, but my instinct tells me, I should help you, by not telling you how to do it; it is very possible that your text will become more blurry after you do the manual adjustment, depending on your skills and level of experience.

HOWEVER, with that in mind, if you are 100% sure you want to do this do these steps in the first place:

1. Enter Service Menu.
2. Go to Test Mode.
3. Go to Test Pattern Output Mode
4. Set the values for ALL colors (CMYK) to 255.
5. Press return.
6. Go to Machine Adjustment -> Printer Adjustment -> Auto Color Registration; conduct it.
7. Go back to the Printer Adjustment -> Manual Color Registration.
8. Press the COPY button on the top left of your touchscreen.
9. Select A3 or 11x17 in paper - I suggest you put ~100 gsm paper -.
10. Select FULL COLOR.
11. Press the START button.
12. The machine should put out an A3 or 11x17 with some lines and crossmarks - black and CMY. Take the paper and put it on the scanning glass, face down. On it, put 5-6 sheets of the same paper type - white, of course.
13. Close the DF or whatever you got on the machine.
14. Press the SERVICE button on the top right of the machine.
15. Press SCAN or START (frankly, I don't remember exactly what button comes up on that screen).
16. The machine will scan the paper and modify the values you have on the table on the screen - corresponding to every value there will be an OK or NG.
17. Take a photo of that screen and attach it to a following post so that I can tell you what to do from that point further.
18. Exit Service Mode.

Hopefully, your machine isn't very screwed up. We will see when you post the picture.

Good Luck!

resolute
05-03-2011, 05:59 PM
Empiru -- Attached is a screen shot as requested...9635

empiru
05-03-2011, 08:33 PM
Ok, great!

We are now starting the hard part of the adjustment. First, you have to open the toner supply unit. There, you will find, corresponding to every color (CMY) a plate, fixed with 2 screws. For Magenta, ONLY, you have to move up or down that plate (be careful, that mechanism is very sensitive - a notch of that plate changes the position of the image by 0,5 pixels). Now, you do the steps I told you all over again, starting with the Auto Color Registration and ending with the scanning of the A3 or 11x17 sheet of paper, until OK is displayed everywhere for Magenta.
Again, I'm telling you, be very careful and very patient, this may take a while to adjust. Or if you are lucky, it could take only 5-10 minutes.
I hope this helps. I'll be here for any other questions!

empiru
05-03-2011, 10:00 PM
Oh, I forgot to tell you this: after every cycle of adjustments, try to print something that was blurry before to see if it's gotten better or worse;
I'm just saying this, because there are misalignments that the human eye can't see.. but the scanner does..

resolute
05-04-2011, 10:53 PM
thanks- i will try that tomorrow - and get back to you.

empiru
05-13-2011, 08:55 AM
Resolute,

Did you try the Manual Adjustment? If yes, did it work?

resolute
05-13-2011, 05:11 PM
Hi - Sorry I did not write back. Easiest way to put this is my technician is a BONE HEAD. They will not make the adjustment, they will not allow me to make the adjustment and now they are blaming the stock. We are running 12PT Carolina C2S stock - it is @ 250gsm - no where near the 300 gsm limit of the machine. We have run this brand of stock from day 1 - probably put 300,000 sheets of this through the machine, auto-dulpex, etc. with very few jams or issues. I have talked to many people that are running 14PT C2S through this machine without issue (simplexed) . It is very frustrating. This problem is on all stock - not only cardstock, they clearly do not have an understanding of the machine and we are facing a disaster as we have invested a lot of money in this machine and because of their lack of servicing knowledge - my business is suffering.

I am meeting with the service manager this week - and there will be some very harsh words.

Thanks for the effort that you put in this - i will let you know how I make out.

empiru
05-14-2011, 06:08 PM
Resolute,

If I were you, I would tell them to bring their own paper and to prove that your paper isn't good. Of course, the machine will misregister the colors on their stock too, and there you go: they will have to help you.

resolute
05-15-2011, 11:01 PM
Empiru - i have decided that my business is more important than the attitude of my tech - so, I am tackling this myself. First thing - I made a pic of where the magenta was before i made any adjustments. I started going up 1 notch at a time - until it was max'd out. Then worked my way down - again, until it reached the lowest setting. Literally 3+ hours to do this. Never got "OK" on all. I would get Error 1, Error 5 and Error 13. What I noticed that when I max'd out the settings, with the magenta at the max DOWN setting - the Magenta was preregistered "UP" significantly (@ 0,5mm) on the Max. UP setting - the magenta was STILL too high - although only by a pixel or so. So - I gather that I have something else that is causing the magenta to not be in the right place???? Any suggestions?

empiru
05-16-2011, 07:52 PM
Resolute,

I can't believe the manual adjustment didn't work... I am sure it took you 3 hours, I know it does... the three errors that you got were only from misplacement of the chart, nothing serious..
I'm trying to think of another solution to your problem... did you change the color registration assy/unit? and if yes, did you conduct the adjustments for replacing this part?
It is situated on the top left of the Transfer Belt and has 3 sensors that determine wether the colors are alligned or not...

resolute
05-16-2011, 09:25 PM
Empiru - I did not change the unit, however, the service tech did - as per the adjustments - I am not sure if they were done. I gave up and bought the 2 service manuals so that I can see what the problem is. I will start this process from the top... If you can offer me any additional information which is not covered in the service manuals - I really would appreciate it... where are you?? (city)

empiru
05-17-2011, 06:41 AM
Resolute,

I will try to help you with everything I can.. right now, I am out of ideas for the solution to your problem, but I will still think of something else..
As for my location, it's in my profile too, city Brasov, from a little and not well appreciated country called Romania...

empiru
06-05-2011, 10:37 PM
Resolute,

Did you find a solution to the problem? Did you talk with the service manager?

resolute
06-07-2011, 07:54 PM
no resolution at all. The machine is still not working properly. We are having to get very creative on running anything through the machine. We are bringing in another machine, so that we can test out to see if it has the same problems. We are hoping the 2nd machine will be here next week.

Herrmann
06-07-2011, 09:50 PM
on the Max. UP setting - the magenta was STILL too high - although only by a pixel or so

That looks, like you are in the right direction, it only seems that you need more room to move. The adjustment Plate is fastend by two screws, remove the lower one, so you have more room up. Maybe this could help you to bring the Adjustment to an happy end. Also compare the Adjustment Parts with the cyan section, to see if something is broken or bent.

Apollo123
06-08-2011, 03:44 AM
Hello it could be a couple different but I had a similar problem which was caused by toner scattering due to much toner being laid down. I fixed my problem by reducing the maximum toner quantity for the the particular color I was having a problem with ( my problem was with cyan). You can locate this in Machine Admin setting. Then go to system settings from there expert settings, Process adjustments and Finally toner/quantity /exposure. After you do this please perform a calibration of the controller You can lower each color individually. If this does not work you may want to check your belt line speed adjustment. It may also be a problem with the fuser since you said it seems to happen more on heaver stock. I have seen blurry of banding copies happen because of slipping one ways in the fuser drive box or cracked collars on the lower fuser roller. And if all else fails you may want to try a Writing Init. Pos. Memory.

Jsh77
08-19-2011, 05:49 PM
Try another paper, it must be the cause...

Custom Search