yellow in 6501

[levino]

Hi,
IN my KM6501 yellow is not uniform
I tried drum,developer,belt,charger and transfer rollers
done the uneven density adj too
no chance

Pls help
tanks in advance
Levi

[HORSE]

what you mean not uniform in the main scan direction (ie. uneven front of machine to back)? Is there yellow blotches through solid greys/browns for instance (moiré)

I would require a bit more detailed information


You mentioned you done the uneven density Adjustment... have you made sure that Yellow is set active? (highlighted green)

[RRodgers]

I didn't see you mention that you did the charge corona and the charge corona's on this box are know to not sit in there holders properly from manufacturing.
Pull your charge corona out and look at the wire. They usually "fall off" the plastic parts that hold them in the center of the housing.

[HORSE]

I didn't see you mention that you did the charge corona and the charge corona's on this box are know to not sit in there holders properly from manufacturing.
Pull your charge corona out and look at the wire. They usually "fall off" the plastic parts that hold them in the center of the housing.

He did mention that he replaced the 'charger' along with all the other parts.

[RRodgers]

Ahh... you are right... I was looking for corona when I scanned what he replace... LOL Still.. it's a known issue and I'd be willing to bet the new one is not set right.

[HORSE]

Yeah but if it had been me I would have swapped the corona around with another colour before fitting a new one

[Stirton.M]

As Horse mentioned, more detail on what is wrong with the yellow is needed. A picture is worth a 1000 words. If you can, do a 53 halftone test page with the yellow and any other colour at a density of 150 each. This will make yellow stand out relative to the other colour and show any defects. Post that image so it is easier for us to visualized the problem.



Following the discussion between RRodgers and Horse, on the extreme end of possibilities, the issue might be related to an uneven drum drive shaft....rotating in a wobble. Swap the yellow drum drive unit with the cyan (they are offset like that in the back). If it moves, there is your problem. If it doesn't move, you at least eliminated that area.

[random]

Assumeing you are seeing this on DOT1.....

Set test chart density to 80 and run test chart 53 alternate dip-sw 3-0 between 1 and 0. Does it improve or make it worse?

[levino]

Hi, tanks to all,

The uneven in the main scan only,I was tried in the dot1 in 53 test pattern with density 70.
Th the new charger replaced was swapped and tested Also I swapped the charger from another machine..AS per Horse i checked and confirmed that Yellow blotches are in the solid gray areas------.I done the density adjustment with yellow only.I can post 53 test pattern tomorrow.This machine run only 45k prints.

[HORSE]

I would try printing solid grey/brown half tone jobs as a Line screen, Line screen often flattens and reduces moiré.

In the Image screen in the fiery job Properties select either Line 1 or Line 2.... You probably will see an improvement.

(I just assumed you are using a Fiery and the job in question is a print job)


Even the 53 internal test print (CMYK Grey) on Dot will give you moire, Print same in Line 1 and see the difference.