Line when printing - but not copying

[costd]

MX-6200 (3 different machines - same location). Started with magenta on machine 1. They appear at random times but in same location (leading to trailing front edge - as in bottom of a page). They will appear lightly, then darken, then fade away to return later on (ex pg 1-14 ok, 15-17 light, 18-22 dark, 23-30 fading, 20 pages ok, then starts again).

I have tried the standard things like changing the drum and MC (3 times in 7 months now), cleaning the laser glass (and looking for something like a hair or dust bunny). Full calibration of both copy and printer. None of the drums appeared to have anything wrong, but the problem goes away for a little while when the drum/mc are replaced as a unit using new drum, mc and cleaner. Last time I changed out the actual unit as well as rebuilding it.

I understand why printing can have it but copying doesn't - my issue is why it is happening. Not a driver issue as more than one user has the same problem (but I reloaded them anyways).

Now I have a 2nd & 3rd machine, same location doing same thing with different colors (cyan and yellow).

Replacing the drum unit with a rebuild works - for a short time.

Ideas?

[Jaws]

Re: Line when printing - but not copying

Sounds like the problem is in the mc unit. I dont try to rebuild them. How much are you saving by changing the drum, blade, and micro charge screen verus buying a complete drum unit???

[costd]

Re: Line when printing - but not copying

Thank you for the reply. As I should have said, I have tried new units (MX-27NUSA) as well as rebuilding with the MX-27NRSA and MX-700MK and new seals/pads as required. Same results.

Replaced the units on all 3 machines again and each drum had significant wear on the ends (more than normal for around 40K). Since I have tried new units I do not think it has anything to do with the way I rebuild them. As for cost/benefit of rebuilding, I just work here - bean counter makes the decisions AND REMEMBER to a bean counter, our time is free. Rebuilt units seem to last about the same length of time so there must be some savings of some kind.

Only thing that I have noticed about these 3 from any other MX-6200 series I service is they do very few copies but lots of printing. As I said before, I understand why it shows in prints first, but am not understanding why printing wears drums/chargers faster than copying?????

I notice there have been quite a few views of the topic and only one response - think maybe I am in uncharted territory. Second trip for me into the unknown. Would ask Sharp but I can already hear them say "Hmmm never happened before".

[mojorolla]

Re: Line when printing - but not copying

Have you cheeked the metering blades in the DV units for clumped up toner? I have a few 7001 that the toner will clump in the DV unit causing random, reoccurring lines. These machines are hyper sensitive to humidity and poor or damp paper. Also, make sure it is a foot from the wall as these need room to breathe. The system will pre-load toner in anticipation of print jobs. This pre-loading will level excess toner in the DV unit which can clump by the metering blade, causing lines. There are a few soft switch setting you can change to purge the excess toner out of the developer.You may notice higher toner consumption, but it does help with the lines. Shoot me a PM and I will give you the list.

[Jaws]

Re: Line when printing - but not copying

Might also check out Bulletin Number:

MFP-SB-456

[Hemlock]

Re: Line when printing - but not copying

Disclaimer: haven't touched a 6200 in 2-3 years.

As for why on prints and not on copies - There are numerous adjustments (usually in the 50s and 60s section of service mode) that will tweak color, charge levels and such specific to the incoming job (copy, print and maybe even faxes on lesser machines - but don't quote me on the last one). This is one of the areas inexperienced techs will tweak rather than doing the necessary cleaning and maintenance.

Another (again, iirc) is within admin mode; you can tweak exposure levels and effect a change that may impact the charge units. Techs that are inexperienced (or lazy) and get a service call for background on copies may not bother to check prints and simply change exposure to placate the customer or get out the door without parts being used. Subsequent tech does a proper drum/developer change and cleaning, fixing the source of the issue, but isn't aware that the exposure has been messed with.

Just theory, but the gist is check all your adjustable settings to see how close or far they are out of the default range.

[costd]

Re: Line when printing - but not copying

JAWS: SB does not apply. Even if I am not rebuilding the units properly, the issue would go away when I put in an MX-27NUSA - and it does not. Thank you for the suggestion though.

HEMLOCK: Whenever I replace a drum unit I do a full calibration. As luck has it, "I be the one" tech for these units and check the setting and calibration with each cleaning.

The real issue is why the drums are wearing faster when they do a lot of printing vs a lot of copying.

I think the DV being over toned might be worth a try.

Thank you everyone for the suggestions. I am going to try the switch settings next time I am down that way.