mx 2300 color problem

[alpererciyaz]

there is a mx2300 machine.the problem is about color.if u get a one copy there is no problem at the copy but whenever i get the 30 or 40 copies with the same copy,there is a porblem about copy.some colours are not seem good just like no toner in the bottle.but there is no problem if u take one copy.

[OMD-227]

Many things to consider here.....

Firstly, is the machine serviced correctly, with good drums/devs/transfer belts and is the firmware up-to-date?

Secondly, what is the toner coverage of each page?

If the print/copy jobs you are doing are a very high coverage over a long run, the Sharp MX machines can have a problem keeping up with color density throughout the job, as the amount of toner going out onto each page, is not being replenished as quick into the developer.

First thing you need to do is make sure the machine has good consumables. Ensure it is fully serviced and up to date. Then run a full color calibration over the machine with sims 46-24 & 67-24. After that, if you know that this particular machine will be doing alot of these high coverage prints with density loss throughout the print run, you need to change the timing of process control execution, so the machine can force more toner into the developer, therefore keep up with the print density required.
This is done in sim 44-28. By default, the machine is set to perform process control by number of pages (either page count or accumulated drum rotation distance). It looks at both of these numbers because some machine might do alot of small jobs, while others might perform long continuous runs.
You need to change the way process control is executed by changing sim 44-28. Change item G to on (off by default) and item N to either 50 or 20 (100 by default). This activates process control execution by looking at toner consumption count (pixels) instead of page count. The default setting of 100 would perform process control after 250 pages at 20% coverage, while a setting of 20 would perform process control after approx 40-50 pages at the same coverage rate.
Basically, its trial and error with your setting number in item N, because no print jobs are ever the same. A certain setting that suits this job, might slow the machine down with excessive process control execution in another job.
Either way, changing the way process control is executed, definitely makes the machine force more toner in to compensate for high coverage print/copy jobs which lead to color density loss from beginning to end of job. However, it slows the machine down a little bit, as it needs to pause and feed toner in while adjusting the density. Make sure your client is aware of this. Its already slow enough as it is only a 23PPM machine.

There is an old bulletin we have here on applying a developer unit auger stirring sheet, which is basically stick-on plastic stirring fingers that are applied to the augers within the dev unit. The theory behind that is to help move the toner throughout the developer faster, as it is only fed in from one end. The quicker the toner can get from the rear side to the front side, maybe the machine could keep up with color density on high coverage jobs. This is not the case at all. I tried this modification on a few clients who print alot of 'poster-prints' where the pages are stuck together to make a large A2 or A1 sized picture. The top left page was always alot darker than the one in the bottom right when it was all stuck together, even with the dev unit auger mods done.
This mod was also made to help with toner becoming lumpy, especially in the black dev of the MX3500 and 4500 series machines, which have the dev units directly below the fuser.

Anyway, color density loss can be mostly solved by changing 44-28 settings I listed above. Its not the perfect fix, but it can help.

[Jimbo1]

What he said.

[rayjeek]

If the colour loss is especially on yellow then run sim 50-22, if it comes out with an error either cleaned/replace the transfer separation clutch on the main drive. The shaft on which the clutch is mounted can be rusted and sometimes e-clip behind the shaft falls off. Pull out the shaft slightly, if it did come out then you have to take the main drive out to fix this problem. Good luck.

[OMD-227]

Yep, Rayjeek has thought of another cause of this issue.

I find that running about 50 sets of self print test 64-05 will show any problems with the main drive unit. Rayjeek is right, the pages will start OK, then the colors will fade off. I find that its always cyan & magenta that drop off if there is a problem with the clutch shaft in the main drive unit, as it loses all power of driving the color transfer rollers down within the transfer belt. The yellow usually works fine because it has an extra tension/follower roller beside the yellow transfer roller.
Basically, if you run sim 64-05 on a continuous test, the first few sets will be fine, then you will notice that the colors will start to disappear. The black will always be OK. If this is the case, you have an issue with the main drive unit (which has an updated part number to resolve this problem).
Another test you can do, is run the transfer load test in sim 6. This will run a continuous transfer cam up/down test, driving the clutch and shaft. If the problem is bad enough, you will eventually get L4-06 trouble code. That is a sure sign the main drive unit is faulty.
This is different from my first post here, as I was thinking your problem was more on density loss across a large copy set.