mx2700 halftone calibration

[cetverooki]

Hi to all

I seem to heave problem with calibration of mx2700. I heave ether made mistake in calibration procedure or I'm missing something (or some steps) in procedure.

Can You please post calibration procedure that you use.
I can not get consistent coverage by any color on page or on print job. (As customer prints color will start to shift)

thx to all.

P.S. i heave service manual but wish to check if what i was doing is correct

[Akitu]

Process control 44-6
Half-tone Correction 44-26
Copy/Print auto calibration 44-74
Calibration as target 63-08

Make sure your internals are all cleaned up before the process control, pay extra attention to the toner density sensors.

[cetverooki]

that is exactly how i do it. I clean whole machine (optics and all parts in imaging section) and then i perform calibration.
i heave 3 machines that exhibit same problem - color density on paper is uneven (there are patches where color is thin and you can see paper beneath) and color starts to shift to darker or lighter shade.

anyone had similar problem?

[Akitu]

You're absolutely positive that TDS in the back is squeaky clean?

Are you able to upload some pictures of what's happening?

[bdcrandall13]

Does it do the same thing when printing either an internal print or a customer print job?

We just had an MX4100n that was not putting yellow or black on the page. After checking consumables it ended up being the TC1 board. Yellow and black voltage was off. We determined that by running a half page test. We stopped a sky shot copy in the middle of the job and looked at all the internals. There was good toner fill on all drums but yellow and black would not transfer to the primary transfer belt. It did the same thing even with a brand new belt in it. After looking at wiring diagram it all came back to the TC1 board which fixed it. If there isn't a good fill on the drum it could be DV or laser shutters. Have seen the laser shutters cause problems a few times on those models.

[cetverooki]

problem is that all 4 colors are off. it affects all of them, even if transfer belt is new.
2 days ago i heave opened machine and cleaned it. cleaned all drums, blades, coronas, put all back, done calibration and got same problem. same problem occured even after changing developers and preforming all calibrations.
same problem i heave on several machines and only thing that connects all of them is me (bad karma??).
Image0003.jpg


Above is what all units print (more or less). If you look at print on part where it should be solid color i get spots where color is thinner. when colors are mixed for regular print it is even more problematic.


regarding other problem.
did anyone encountered that when print job is sent to machine (for example 400 pages) prints start to shift in color shade. slowly but at the end of print colors is visibly shifted and even not close to original. this happens too when machine stops to cool down or when paper tray is empty.

[divad2k1]

How old are your drums and dv ?

[bdcrandall13]

Do you have the actual Sharp calibration guide? It is hard to tell by that scan what you are talking about. They grey's look a little off and the magenta looks like you need to adjust the laser, but other than that it looks ok. PM me your email and I can send the guide to you. What type of paper are you using? Sharp specifically asks for Hammermill 28 lb color copy paper when calibrating. We use it every time. If you use a regular 20 lb sheet of paper there is a chance the calibration won't be as good and one of the symptoms is bad fill. Also, printing/copying on a 20 lb sheet of paper will never give you near the quality as it will on a nicer sheet of paper like Hammermill's 24 lb laser print or 28 lb color copy paper. Just a thought...

[Dark Helmet]

From what i can see on your sample yellow is the only color that is giving these lines or blank spots that show white on the paper in the half tone area's. Yellow solids look fine. Red and Green are affected as well since yellow is used to make those colors.

You could try to use Sim 64-1 and make pure yellow pages, Start lowering the density until these lines start to form. Set the multi count to 5 or something and jam the machine so you will have image on the transfer belt and image on the drum. You can start narrowing down the problem from there.

Maybe you have a dirty transfer roller in the primary belt and your not getting good transfer of the half tones.

To be honest for me those look like laser but i would be suspicious of 3 machines all doing that.

[Akitu]

Cleaned the drums and blades? What?

If you actually did that you may have potentially light shocked your drums just from having them out...

[mojorolla]

Have you run 50-22 and 61-04 ? This is the adjustment for how the colors are layed on the belt. I always run this before calibration. Also, run 44-27. This will scrap the old target and allow you to start from scratch. I also use the best paper possible. The better the paper, the better the calibartion.

[cetverooki]

i heave lengthy calibration procedure taht includes drum rotation and all.

problem is that all machines heave done various number of total copies. all are exhibiting same problem (to a various degree) and i remember copy quality when all was ok (when they were rather new). I remember clearly copying front page of magazine which was with a lot of solid color and i was getting exact copy. so much so that it was nearly impossible to differentiate which one is original. now i can barely get a copy that is acceptable for presentation.
since it is not only one machine i had to ask myself if i'm the problem or rather my calibration procedure.

@ bdcrandall13
i don't remember which paper was exactly but it was something along what sharp recommends. i will double check this next week. as for procedure i heave all documentation.

@ Lawrence
i will print 64-1 and post them. they are even worst than what i heave posted. this problem has been bugging me for some time and i can not find solution or cause of this problem. and laser could be a problem if colors were weaker on one side, but that is not case here. i heave cleaned laser on one unit and on other i had to replace it (got an error for lsu)

@Akitu
yes, well drums were stored safely. i always try to start calibration with machine that is cleaned and brougt to point that is as close to factory state as possible.

[bdcrandall13]

Run a half page test with an original that you are experiencing the problems with. See if the defect is on the drum or if it is just not transferring well. You can use 64-1 to do this effectively.

[divad2k1]

Have you changed your drums, dv , charge , blade ...beside cleaning them ?


Whats the copy count on your copier ?

[Toner Boy]

If you change the whole primary belt unit, make sure all of the charge rollers are in proper position. Our last 3 belt units had one roller out of its cradle. Make sure you are using proper paper for calibration, 5 white sheets on top of calibration printout, and no damp paper in machine. The secondary TX belts get old and stiff on low-use machines, won't spin right and give crappy transfer of image.