MX7500 blowing toner like crazy

[dm10901234]

Customer printing training manuals. Within about 125000 prints they complain about quality. We look in the machine and there's toner everywhere.
20180118_150129.jpg20180118_135309.jpg

Using Sharp original toner.

They have 2 MX7500's, they both do it. One is a lot newer than the other. One has 1.5M on both color and black, other has about 800K on each.
We replaced the whole primary transfer unit on the old one, problem still happens.
Complete recalibrations are being done. Current firmware.
This is after all developers re-started.
Ordering drum frames next.

Anyone else experience this?

[spanky]

Have toner filters on the top of the dev units been replaced.

If so replace dev unit.

[DavePo]

What is the humidity level reading in TC 44-14? We had one last year in January that did this exact thing. The Humidity in the room was less than 10%. When humidity gets that low machine can't process and goes to a high humidity gamut in process control. Our customer had a new humidifying system installed and has helped tremendously.

[dm10901234]

Thanks will check into the humidity. I know it's very dry there.
I see the manual specs humidity at 20% to 85%. Looks like it may be possible to disable humidity correction in sim 44-1?

"The fluctuation in the transfer efficiency due to the
temperature and humidity (absolute moisture) is
corrected. Enable/Disable setting. Correction of the
output voltage of the transfer high voltage"

Will see...

[Luke123]

if the problem comes back I would agree with Spanky it is time to replace the DV units.They have a lot on copies on them. Have you also checked to see the amount of toner the customer is using on the copies they are running. Example if they are running a heavy coverage of Cyan the dv unit can get very over toned early,and cause a lot of dusting.

[Craigcul]

Hi have you checked the machine filters and dv filters if they are blocked the toner will also blow out another thing could be the DV as well do a 22-06 to check what life is left on the drums and DV

[mojorolla]

These units are known for dustng, usually magenta and yellow, just like your pic, inside the belt and pretty much anywhere else....
As suggested above, the dv filters are a big deal. Sharp DV filters are absolute shit if you vacuum them and they WILL pull the filter material onto the mag roll, causing voids.

There is a retrofitted cleaner unit with beefier seals. There are retrofitted charge units with the tapped ends. If the machine is attached to a Fiery, make sure the customer is calibrating frequently. The belt you show in the pic seems to happen with non calibrated Fiery controllers. I have also seen the waste toner auger in the front door get clogged up. While it is by no means a fun task, it is a few screws on the back side of the front cover. And, believe it or not, it actually has a metal auger, metal is so rare now a days.....

I would also check the paper stock they are using. Although Sharp bills this machine as a "light Production", I would call this more of a "heavy office color" type unit. It has severe limitations when it comes to booklets. Customer will often tell the machine a lessor paper type to get the finisher to fold or staple heavier stocks.
Calibrate as follow:
50-22
44-2
44-6
44-26
61-13, reboot, 61-11
46-76
If the Fiery is attached, calibrate it after the engine. If it has the ES-2000 spectrometer, use it for best results. If not, use the pattern with the multiple patches.

[dsmith46]

Don't forget to do a 44-27 before executing 44-6 and 44-26. This ensures the halftone data is correctly stored.