Roland LEJ-640 Print Head Issue

[Signs4Realtors]

Thanks in advance for any input on my Roland LEJ-640 print issue. I have been using this printer for many years with no big issues, but I need help figuring out why there is a "drop shadow" printing around my C=0, M=0, Y=0, K=100 black ink only when I am printing in high quality mode (there is no issue when printing on high speed low quality fast mode)? The print below

I know that there is an issue with my Yellow as it barely prints on high quality mode (see yellow lettering below on left), yet prints perfectly in the high speed fast mode and on the small test prints (see yellow lettering below on right). Also, the black lettering prints fine on high speed, yet on the image below the black has a yellowish drop shadow around the letters which was printed on high quality mode.

The print below is in high speed mode and prints fine.

 

[Solventinkjet]

Your yellow head is probably on it's way out. These heads can print multiple sized dots. When printing in high speed, low res, it uses a single sized, large dot. When printing in high quality mode, it uses the other sizes together to create the best print. So basically think of it as the head having two modes and one mode can become damaged and the other not. It usually indicates that it's an older head or there was some electrical damage to it.

 

[Signs4Realtors]

Your yellow head is probably on it's way out. These heads can print multiple sized dots. When printing in high speed, low res, it uses a single sized, large dot. When printing in high quality mode, it uses the other sizes together to create the best print. So basically think of it as the head having two modes and one mode can become damaged and the other not. It usually indicates that it's an older head or there was some electrical damage to it.

Thank you for the input. I definitely think the yellow head needs to be replaced. What about the black head (see drop shadow in the Roland logo below....it's yellowish color)? When I print Black in high quality mode there is a drop shadow behind the lettering/graphic which looks yellowish? I did a test print with only K=100 and Y=0, C=0 and M=0. Why would the bad yellow head print a yellowish drop shadow on the 100% black test print? Might this mean that the Black head also needs to be replaced or is this the Yellow head causing this problem also?

 

[cornholio]

Set it to "linearisation and ink limit only" otherwise the profile will add colors to a 100% black.