Mp 9000 random smudge... I'm gone mad!

[NeoMatrix]

I've refined my corona cleaning technique:

I pour 1/4 cup of alcohol in a small glass jar. I dip wood handled cotton swabs and swab out the housing. Glass cleaner can short out the blocks, doesn't clean off the ozone as well as I'd like, and does not evaporate as well as alcohol. Then I dip another cotton swab and run it along the edge of the housing under the wire, back and forth 3 times. Then on top of the wire (resting on the edge of the housing) 3 times. Flip the unit lengthwise and again 3 times under the wire, 3 times over the wire.

Next, I lay down a section of newspaper with the grid on top. Dip a toothbrush in the alcohol and scrub the grid in the direction of the diagonal grid pattern, usually left handed on the inside, right handed on the outside. Move the scrubbed grid onto a fresh/clean section of the paper and using your forefinger squeegee the alcohol off of the grid, both sides. If there are any wrinkles or burned marks that the alcohol won't remove, you can stop right there. It's not worth continuing to clean a damaged grid. You won't get an even halftone.

I know it sounds a bit complicated, but you can clean a corona unit in about 6 minutes with a little practice. You'll see a surprising amount of ozone on the newspaper when the alcohol dries. =^..^=

A small piece of wet and dry sandpaper on the corona grid works very well. It will clean Sharp PCU corona grids very nice, which will remove the mysterious ghosting smudge marks that drives some Techs crazy while trying to locate the fault.

Tip for the new guys starting out:
*** Sand papering the corona grid must be done "CAREFULLY", while working in "ONE" direction only... ***

[Phil B.]

A small piece of wet and dry sandpaper on the corona grid works very well. It will clean Sharp PCU corona grids very nice, which will remove the mysterious ghosting smudge marks that drives some Techs crazy while trying to locate the fault.

Tip for the new guys starting out:
*** Sand papering the corona grid must be done "CAREFULLY", while working in "ONE" direction only... ***

I use a bit of green "scrubbie pad" on hemostats to clean ANY wire and grid! ** watch for fibers**

[Mark Bbb]

About 10-15 degrees Celsius

Inviato dal mio SM-G935F utilizzando Tapatalk

This flutuation is very big!
Is the machine standing in a garage, kitchen or bathroom or any other room where water is been used?

[Codex]

This flutuation is very big!
Is the machine standing in a garage, kitchen or bathroom or any other room where water is been used?

No.. It's in a dry room

Inviato dal mio SM-G935F utilizzando Tapatalk

[Codex]

Guys... After almost three weeks without problem.... This morning the problem was back again for a few copies/prints... The last thing i changed three weeks ago was the black lamp assembly, together with the 2nd cleaning blade mechanism........ I think i need a priest now... Or an exorcist

Inviato dal mio SM-G935F utilizzando Tapatalk

[Mark Bbb]

No.. It's in a dry room

Inviato dal mio SM-G935F utilizzando Tapatalk

What kind of room is it?
Is there a working ventilation system or not at all?
How often is the air turned over in that room?
I think that the room has no ventilation at all, and that the only ventilation is done by opening the door ...
The less this door is opened the more moisture fills the air and v.v.

[imaginemoko]

what's our PM count? pre charged and charged unit and in cleaned? like no arching on where the spot appear? is the charged frame are free from worn out like a foam seals from ozone filter and its frame? development unit entrance seal is good, like some toner may came up to charge unit? when swapping parts does it appear same time for a few copies it will appear? may i suggest after cleaning the charged unit just leave the right side, side cover and run the auto process then run some jobs for observation, best of luck Sir.

[Codex]

A small piece of wet and dry sandpaper on the corona grid works very well. It will clean Sharp PCU corona grids very nice, which will remove the mysterious ghosting smudge marks that drives some Techs crazy while trying to locate the fault.

Tip for the new guys starting out:
*** Sand papering the corona grid must be done "CAREFULLY", while working in "ONE" direction only... ***

Already changed the charge unit and the 2nd charge unit first from a working machine, and then Grid and wire (new and original)...."Ghost"appears anyway...

[Codex]

What kind of room is it?
Is there a working ventilation system or not at all?
How often is the air turned over in that room?
I think that the room has no ventilation at all, and that the only ventilation is done by opening the door ...
The less this door is opened the more moisture fills the air and v.v.

The machine is situated in a Copyshop in Messina (Sicily),the problem starts last winter and till now it's not solved, so i think it's not a temperature problem, the shop is ventilated because the customer leaves the door open summer and Winter...there is an airflow in the shop and the machine is not attached to a wall, there are 15cm of space behind the machine, the filter was cleaned during a PM,in the shop are 7 other machines (Aficio 2075 and one MP 5500 and one MP 7500) no other machine has similar problems.

[davel]

Sounds like this print shop needs to update all of it's old machines.