C1 imagepress copy quality question

[mark921]

Hi guys;

One of our C1's has an issue with the prints getting gradually darker on longer runs. After about 250 prints, the prints begin to become darker and become more intense. The drum has roughly 100,000 impressions, and the developers have just been changed, and the coronas and grid are new. the image always comes back after a full gradation adjust. Any thoughts? As always, i greatly appreciate any input...

Mark

[Van Steal]

Re: C1 imagepress copy quality question

Hi guys;

One of our C1's has an issue with the prints getting gradually darker on longer runs. After about 250 prints, the prints begin to become darker and become more intense. The drum has roughly 100,000 impressions, and the developers have just been changed, and the coronas and grid are new. the image always comes back after a full gradation adjust. Any thoughts? As always, i greatly appreciate any input...

Mark

I'd change the drum the life is only 50'000 prints, I think, but if your printing A3 thats only 25K.

[mark921]

Re: C1 imagepress copy quality question

Chances are the drum is going, but the yield on these drums are 250,000 prints.

[mark921]

Re: C1 imagepress copy quality question

sorry....150,000, not 250,000....typo

[zoraldinho]

Re: C1 imagepress copy quality question

Probably drop down drum temperature.Start with last firmware.Try with drum heater ON.Make full
gradation and rip calibration.Try to found out on how many prints machine adjust auto gradation.

[teckat]

Re: C1 imagepress copy quality question

Hi guys;

One of our C1's has an issue with the prints getting gradually darker on longer runs. After about 250 prints, the prints begin to become darker and become more intense. The drum has roughly 100,000 impressions, and the developers have just been changed, and the coronas and grid are new. the image always comes back after a full gradation adjust. Any thoughts? As always, i greatly appreciate any input...

Mark

what %pct. of color is output on paper

how often do u calibrate ???
do u have a fiery ?? do u use Kodak grey scale for calibration ?
how is the Grid Bias ???

[mark921]

Re: C1 imagepress copy quality question

Teckat, we calibrate every 500 copies...roughly. This particular machine is primarily for down and dirty prints...mainly flyers, graphs, etc. Percentage of color to b/w varies, but usually is around 80 percent color. (estimated) Our calibration routine is as follows...full calibration from the copier, followed by the Kodak gray scale calibration from command workstation. We also do this routine when we go from coated to uncoated, and text weight to cover weight. We use Q1 rips on all of our C1's. I will check the grid bias in the morning.

Zoraldino...the drum heater is on. I'm not sure how to drop down the temp, however.

Thanks again for the input..

[teckat]

Re: C1 imagepress copy quality question

Teckat, we calibrate every 500 copies...roughly. This particular machine is primarily for down and dirty prints...mainly flyers, graphs, etc. Percentage of color to b/w varies, but usually is around 80 percent color. (estimated) Our calibration routine is as follows...full calibration from the copier, followed by the Kodak gray scale calibration from command workstation. We also do this routine when we go from coated to uncoated, and text weight to cover weight. We use Q1 rips on all of our C1's. I will check the grid bias in the morning.

Zoraldino...the drum heater is on. I'm not sure how to drop down the temp, however.

Thanks again for the input..

make sure u have the latest FIRMWARE,
there was a DCON v21.01 update last year that addressed how density decreases after Auto Gradation Correction
and VDC ( voltage in dark areas)


U'r printing at 85% coverage

this is not a printing press

what's the wkly/month-volume on that % use ??

remember the DRUM life quality is rated at 5/6% text PLAIN LTR usage by Canon
see Canon 6% doc-pdf-

Your Drum is probably TOAST

here is a good pdf on DRUM life issues--READ attached PDF
As the Drum rotates against the Front Seal Plate and the Rear Seal Plate --abrasions begin to develop
and will eventually wear through the Drum outer surface.
Once this occurs the Drum could possibly begin to leak its Potential Voltage through the worn areas; which leads to Drum failure.
DRUM.JPG

[Penvy]

Re: C1 imagepress copy quality question

HI there,
Its been a while folks but my 2 cents..............
I know this "wonderful" copier very well in the developer, image, issues

One thing I know for sure is those developers leak, mainly the BK, but thats
something you would see.

AND those G Damn Developers are too friggin small......period!

Its a royal pIA but have you pulled the Drum assy and cleaned the patch sensors/led assy's/ATR lately?????
They build up fast and IF theres just a little the C1 can adjust, BUT...............BUT cleaning them
REALLY cleaning all of the arrays and sensors will help BIG time with the Auto Grad. adj

Remember the patch sensors read all the time and after so many copies will start to degrade in their ability to read within paramaters.

Just my 2 cents
P


BTW

TEC
I got a good one for you in my next post
Touch Screen crap on the C1

OH JOY.......

[mark921]

Re: C1 imagepress copy quality question

I'll have the drum changed in the morning. Seal plates as well. Volume on this unit is roughly 40k per month. The drum shows a bit of wear where it contacts theseal plates, but nothing too extreme. We realize it's not a press, but the customers love the image quality...so we admittedly use it beyond its rating. . Thanks for the input!

[mark921]

Re: C1 imagepress copy quality question

Penvy, yes. We also have learned this is a very service intensive unit. The ATR and patch sensors are cleaned regularly. and by cleaning, I mean dismantled and cleaned. As for the developers....you are correct, they are too small...and yes they do leak.However...the C1 still makes a great copy!

[Penvy]

Re: C1 imagepress copy quality question

That we can agree on Great copy!
Dont think its the drum, even with the potential sensor on the drum.
Temp can have the effect on the drum surface after a few hundred ,
but thats extreme over 100 degrees +

I am waiting for TEK to chime in on me about this one
P

[teckat]

Re: C1 imagepress copy quality question

6% color coverage @ 120,000 CPM= average tech headaches
85% color coverage @ 40,000 CPM= extreme tech brain damage

would love to see a PIC of Drum surface


pg1.JPG
pg2.JPG

pg3.JPG

[mark921]

Re: C1 imagepress copy quality question

Teckat...I changed the drum yesterday, and had a run of 500 prints after the change. It worked great. Turns out it was drum fatigue.

Here are the pics you requested, and as i mentioned, the side seals have not ground it down to the point it was grounding out. Thanks again for all the help!

photo.JPGphoto2.JPG

[teckat]

Re: C1 imagepress copy quality question

Teckat...I changed the drum yesterday, and had a run of 500 prints after the change. It worked great. Turns out it was drum fatigue.

Here are the pics you requested, and as i mentioned, the side seals have not ground it down to the point it was grounding out. Thanks again for all the help!

[ATTACH=CONFIG]13332[/ATTACH][ATTACH=CONFIG]13333[/ATTACH]

Thanks & Good Luck