c451 Graduation error Yellow and Cyan

[raplma]

Hi all
I know these machines are pretty much obsolete, however we have an old one in the corner just for envelopes as it tends to be more flexible and forgiving than our production machines. Not used since February, and was moved to a new corner in the factory yesterday and when tested was found to print solids but not graduation of Yellow and Cyan - see below pic.

WP_20180514_17_23_25_Pro.jpg

From the pic above you'll notice that there is an issue with graduation. I know our production machines infinitely better than these so I would be most appreciative of any pointers before it gets recycled. All consumables are within service. This particular machine also has the graduation adjustment feature still available within the service menu - Image Process Adj -> Graduation Adj - however when you select any of the three options - Graduation mode etc. - they do not run. For the record it runs through a fiery controller and has 470k on the clock.

Any thoughts?? What am I missing??

Huge thanks in advance,
Mark

[Phil B.]

Re: c451 Graduation error Yellow and Cyan

Hi all
I know these machines are pretty much obsolete, however we have an old one in the corner just for envelopes as it tends to be more flexible and forgiving than our production machines. Not used since February, and was moved to a new corner in the factory yesterday and when tested was found to print solids but not graduation of Yellow and Cyan - see below pic.

[ATTACH=CONFIG]39684[/ATTACH]

From the pic above you'll notice that there is an issue with graduation. I know our production machines infinitely better than these so I would be most appreciative of any pointers before it gets recycled. All consumables are within service. This particular machine also has the graduation adjustment feature still available within the service menu - Image Process Adj -> Graduation Adj - however when you select any of the three options - Graduation mode etc. - they do not run. For the record it runs through a fiery controller and has 470k on the clock.
Any thoughts?? What am I missing??
Huge thanks in advance,
Mark

have you tried cleaning the LSU's?
what if you do a 'stop test'...is the image properly displayed on the belt?
help a little if we knew what you have/haven't done!

[raplma]

Re: c451 Graduation error Yellow and Cyan

Thanks for replying and good point, more detail...

Having moved the machine, I ran a simple B/W job, and discovered that the black IU had failed and dumped onto the Printhead as they do. So removed all IU's cleaned out the Printhead area of toner/dev and cleaned the Printhead laser apertures. Installed new black IU. Ran the image stabilization. Ran B/W job looked ok.

Ran colour job and discovered issue.
Agitated all toners, and swapped yellow and Cyan IU's with items known to be working when removed from another machine, but not new items. (I do have new ones if considered worth while) entered gradation adj menu, ran stabilizer and then found the three further operations - gradation, resolution and high compression - although available were not operational i.e. the start button remaining orange upon selection - yes there was paper in all the the trays A3 being the largest in bypass and tray 1 and correctly set.

In test mode, printed out the various image tests, any of the layouts that use solids are fine - halftone on 255 density, Lattice pattern on 255 density etc. - print out fine, it's when there is a gradation of yellow or cyan that they are not. So in the color sample again any patches that use gradations of yellow and cyan were either missing or incorrect.

Good suggestion on the stop test, will try that in the morning.
I also have a spare printhead which I did toy with swapping over, subject to the suggestions on here.

Dumb question if I may, when you use the terms LSU's what are you referring to, want to make sure I have it correct.

Thanks again
Mark

[Phil B.]

Re: c451 Graduation error Yellow and Cyan

Thanks for replying and good point, more detail...

Having moved the machine, I ran a simple B/W job, and discovered that the black IU had failed and dumped onto the Printhead as they do. So removed all IU's cleaned out the Printhead area of toner/dev and cleaned the Printhead laser apertures. Installed new black IU. Ran the image stabilization. Ran B/W job looked ok.

Ran colour job and discovered issue.
Agitated all toners, and swapped yellow and Cyan IU's with items known to be working when removed from another machine, but not new items. (I do have new ones if considered worth while) entered gradation adj menu, ran stabilizer and then found the three further operations - gradation, resolution and high compression - although available were not operational i.e. the start button remaining orange upon selection - yes there was paper in all the the trays A3 being the largest in bypass and tray 1 and correctly set.
In test mode, printed out the various image tests, any of the layouts that use solids are fine - halftone on 255 density, Lattice pattern on 255 density etc. - print out fine, it's when there is a gradation of yellow or cyan that they are not. So in the color sample again any patches that use gradations of yellow and cyan were either missing or incorrect.
Good suggestion on the stop test, will try that in the morning.
I also have a spare printhead which I did toy with swapping over, subject to the suggestions on here.
Dumb question if I may, when you use the terms LSU's what are you referring to, want to make sure I have it correct.
Thanks again
Mark

LSU or printhead same thing Laser Scanner Unit

[907tec]

Re: c451 Graduation error Yellow and Cyan

Are you getting P-codes? I would be surprised if this problem didn't generate warnings during startup/calibration. Before replacing the printhead, I would make absolutely sure that the IDC sensors and the shutters are in good shape.

I'm not understanding your description of the work you've already performed: did you have the same gradation issue when you tried the other imaging units? This machine has a single print head for all colors, so it's pretty rare for an issue like this to occur with only cyan and yellow. I would concentrate on IDC sensors, Primary transfer rollers/contacts inside the transfer belt, and the HV contacts/board for cyan and yellow.

[raplma]

Re: c451 Graduation error Yellow and Cyan

Yep that was it, IDC sensor.

I happened to have another sensor unit, so swapped it over and bingo sorted.
So massive thanks 907tec and Phil B we got there even with my sparse detail.
For the record the tests I was running were nothing more than those in the Test Mode that check various image states. And no error codes at all, I was surprised as you.
Having swapped the sensor unit I was able to run all the gradation adjustments and below you'll agree is some improvement on the original pic.

Thanks again
Mark

WP_20180516_09_17_53_Pro.jpg

[Phil B.]

Re: c451 Graduation error Yellow and Cyan

Yep that was it, IDC sensor.

I happened to have another sensor unit, so swapped it over and bingo sorted.
So massive thanks 907tec and Phil B we got there even with my sparse detail.
For the record the tests I was running were nothing more than those in the Test Mode that check various image states. And no error codes at all, I was surprised as you.
Having swapped the sensor unit I was able to run all the gradation adjustments and below you'll agree is some improvement on the original pic.

Thanks again
Mark

[ATTACH=CONFIG]39685[/ATTACH]

good to hear!

[907tec]

Re: c451 Graduation error Yellow and Cyan

The warning codes are kind of "hidden", if you don't know where to look. On the main copy screen, there was (probably) a small exclamation point. If you click that exclamation point, it will show you the minor "warnings" that are present (i.e. "L1", "L2", "P5", "P28"). When certain codes are present (P5= Front IDC Failure, P28=Rear IDC Failure), the machine will not allow you to run gradation adjustments. That's why I inquired about any warning codes that might be active.

It's pretty rare for the sensors to actually go bad, I usually just find that they are extremely dirty. A handful of times, I have found something interfering with the shutter mechanism that covers the IDC's.