imagePRESS C1

[banginbishop]

Having an ongoing problem with the above machine in that it produces intermitent lines (see attached).

The machines done about 150k, its recently had the coronas done etc and it was doing it before they were changed. I've stripped out the secondry transfere unit and checked the brass connectors, checked the itb belt unit. The lines have never appeared when i'm there but as you can see it is doing it and its not a normal line the copy is showing signs of dev as well as toner (gritty feel).

I've had to crop the image as they are from a confidential document and the lines go from lead edge all the way across.

Drum has been changed from what i do know - the copies when printing out as normal are perfect.

any help much appreciated.

[Guest]

Gritty feel, Have you thought about changing the developer. That gritty feel is sometimes an indication that its time change developer.

[Oze]

Do you have figures for the life of the dev units?
C1 devs "can't" be restarted(or at least..Canon don't supply starter for the devs)and you have to buy new units with starter already added.
But I reckon iRC6800 starter would do the job(DON'T QUOTE ME)

[banginbishop]

Dev is 500k on these and starter is included. The machine is way off the target and it only does it part of the way through a copy. e.g if you do a full shot of a magazine only a 3 cm wide strip would be of a grity feel and the rest of the copy perfect

[Van Steal]

I've had this problem before turned out to be the drum...not clear if you replaced the drum or someone else and if so make sure you replace the seal plates as well, these wear into drum and cause it to arc.
good luck

[Penvy]

Hi Guys,
The posts I have offered here all point to the dev units
But now that I have seen the pics
Its the dev units and replacement is one option.
the other is to vac out all the toner/dispersant- out of each color
and restart the unit if you can find the powder/toner

the irc6800 was offered .........as long as the "vtoner" is the correct toner
in the refresh/restart.

the only thing is NOT to put too much toner at first,let the copier do that.
Just enough to get the "brush color up" for each.

then run 11x17 full dens on each color in svc mode untill the dens % is within specs.
The dev units themselves are not worn out its the toner "iron oxide" mag powder is too low!!!!!!!!!!

the units are too small to hold enough to that 500K myth

Its NOT the drum.

[CBSPJ]

Check the drum ground

I had a similar C1 and we put a grounding brush on the drum cavity to insure a good ground. If the drum cant properly discharge it will build up the charge and attract developer... Hope that helps

[Penvy]

Very true,
The discharge brush contact cannot be even a little dirty.
The point here is this mach were talking about is only 75K.

Not much chance to get that dirty or "fail"

What I am trying to make clear is the Dev color units are too SMALL!!!
The overall design is not made for any type of volume production.

Its a "proof" color copier that was being forced on the sales staff to sell
as a production copier.

The customer has no knowledge of the performance in the field until its too late..................AND THEY KNOW IT!

[blackcat4866]

Since I haven't seen this particular Canon I can only offer some theoretical comments.

It appears from your samples that developer is being pulled from each of the color developing units at different times. There are only a few reasons that developer will get pulled.

For me, the most likely scenario is a primary charger arcing to the drum. That's when the developer gets pulled, and not necessarily evenly. I don't know the geography of this machine (4 drums & chargers or 1 drum & charger). Based on your samples I would deduce that there is a single drum and charger that only pulled developer when that particular color developing unit was in proximity. The bad news is that when you fix the charge issue, you'll probably have to replace the developing units also, if too much developer has been pulled.

I find it unlikely that the starter itself is dead/spent, or you would see the same effect evenly across the entire width of the page on all pages, not intermittently. If you had some sort of foreign matter in a single developing unit it would cause developer dumping, but not affect the other colors in any way. It would be too much of a coincedence to have multiple developing units all with foreign matter obstructions.

I'll be curious what you discover.

-^..^= (Oops, I lost one of my whiskers...)

[Penvy]

You are correct.
1 drum 1 prim charger and grid
But no arcing...this mach would have some kind of error if that was going on.
It monitors itself very well.
and there would be some kind of marking on the drum.

It make sense , that would pull the dev off the mag roll.
The starter/toner unit just does not have enough physical internal space
to contain enough "mix" to do the full bleeds past 75K as far as we have seen on this one .

Shame that there could be enough space inside the dev drum unit to make them bigger. The mix also depends on the rotation of the
drum for the gravity to toss around the mix inside the dev unit.


A simple refresh starter kit and a vac could fix every 100K.
the seal on the toner supply/waste could be a soft solid silicone
rather that the cheap foam thats on there now.

[CANONNEW]