MX6070N blk pulling developer

**bilyahn** · 04-20-2021

I checked this post out. Sharp MX6070 F4-20 EE-EL Issue

Not quite the same as ours. We have a MX6070 that is pulling developer on a regular basis. The time frame varies from a couple of months to a week or so. Machine has 198K black and 312K color,
firmware is current. Not having issues with the color drums just black.

Have replaced process unit, developer unit and primary transfer belt (some several times). All of sim 8-1, 8-2 and 8-6 are correct. Charge does not get contaminated normally, it will pull developer by having an excess amount on the drum towards the rear frame and dumping it into the waste container which fills up abnormally fast. All grounds appear to be good. Here is a picture of what the drum looks like

20210319_092659.jpg

If you feel the drum you can tell there is a lot of DV material.

Thank you in advance for your time and effort in this matter.

Bil

**blackcat4866** · 04-21-2021

I'll assume that you're new process unit has a new primary charge in it. If I saw this issue, I would assume that the primary charge unit is unevenly positioned too close to the drum on the side that's pulling developer. Corona, needle electrode, or roller primary charge? =^..^=

**bilyahn** · 04-21-2021

Originally Posted by blackcat4866

I'll assume that you're new process unit has a new primary charge in it. If I saw this issue, I would assume that the primary charge unit is unevenly positioned too close to the drum on the side that's pulling developer. Corona, needle electrode, or roller primary charge? =^..^=

Yes, new drum and charge in each instance. Sawtooth corona I guess you would call it. It has occurred pretty much that same with both process units. Maybe we need to check to see if there is a modified/upgraded unit and make sure we have the correct one. Not much I can do about the positioning of the charge unit, it slides in from the front but I will check to see if there is a problem with it's positioning. I would think that the charge would get contaminated if this was the problem? I should mention that I have swapped process units with color ones and the problem doesn't follow the drum, it is specific to black.

Thank you for the response

Bil

**copiertec** · 04-21-2021

Have you replaced the BLACK Developing unit with the latest updated one (DUNT-9290DS36)? There were a ton of updates on it. All so make sure the doctor blade cover is installed correctly, so the pins on either end of the cover are seated properly and the doctor blade cover is flush with the developing unit frame.

**bilyahn** · 04-21-2021

Originally Posted by copiertec

Have you replaced the BLACK Developing unit with the latest updated one (DUNT-9290DS36)? There were a ton of updates on it. All so make sure the doctor blade cover is installed correctly, so the pins on either end of the cover are seated properly and the doctor blade cover is flush with the developing unit frame.

I believe it is but we have swapped out so many developer units in the last couple of years I am not 100% sure. Cover is flush as far as I can tell snaps into place without having to be forced and looks good.

Bil

**copiertec** · 04-21-2021

Originally Posted by bilyahn

I believe it is but we have swapped out so many developer units in the last couple of years I am not 100% sure. Cover is flush as far as I can tell snaps into place without having to be forced and looks good.

Bil

Just to make sure, you can pull out the developing unit and I believe the P/N is located to the left.

**EasyRider** · 04-21-2021

Because Sharp keeps changing the part numbers so often on these DV box and DV units, see Bulletin CCE-2305 dated April 2021 for the current part numbers. (as of this writing)

**mommok** · 04-21-2021

had a simular issue, ended up replacing dv unit, drum unit and hc pwb. problem hasnt returned

**kdr363** · 04-21-2021

Try executing sim 5-4 without drum and dv units installed to check the discharge lamps. It is very tiny in size and often gets dusted with toner and greatly reduces the led output. If bad dirty, it will pull dv.

**tsbservice** · 04-21-2021

Originally Posted by kdr363

Try executing sim 5-4 without drum and dv units installed to check the discharge lamps. It is very tiny in size and often gets dusted with toner and greatly reduces the led output. If bad dirty, it will pull dv.

I don't do Sharp but this sounds more than possible. Parts of drum surface will be constantly overcharged due to bad discharge thus pulling developer along with toner. Fortunately in all brands very rare cases nowadays.