Sp-300v - Color Shift After Head Soak ???

[Sign Works]

Can't figure out why colors are off after head soak. Test print looks good, I can even print CMYK file preserving primary colors and all colors look great but when I attempt to print previous jobs the blue for example is way off, what used to print as a royal blue is now a dark greenish blue. During the extended head soak magenta backed up into the yellow but I printed several large blocks of solid yellow to flush all magenta from yellow damper. What could have occurred that would cause the color shift? What am I overlooking or what did I screw up? My only guess is to change dampers and see if that corrects it.

 

[MikePro]

what was reason for the soak?
missing nozzles in a print WILL shift the color, as will regaining nozzles from a cleaning.

royal blue is made is cyan and magenta, green is made from yellow and cyan.
if you're getting greenish blue, then you've either got yellow ink contamination somewhere, or you chose your original "royal-blue" color based on whatever condition your printhead was firing at prior to the soak. If you regained nozzles from the cleaning, then your color will be different than originally printed with deflected nozzles.

 

[Solventinkjet]

MikePro is correct. Also, it sounds like you could have a persistent cross-contamination problem. The fact that the blue you are printing is greenish tells me that yellow might be printing where magenta should be. Are you 100% sure that you got all of the magenta out of the yellow line? If so, it's possible that the head is damaged internally and/or the cap top is not draining properly.

 

[Sign Works]

what was reason for the soak?
missing nozzles in a print WILL shift the color, as will regaining nozzles from a cleaning.

royal blue is made is cyan and magenta, green is made from yellow and cyan.
if you're getting greenish blue, then you've either got yellow ink contamination somewhere, or you chose your original "royal-blue" color based on whatever condition your printhead was firing at prior to the soak. If you regained nozzles from the cleaning, then your color will be different than originally printed with deflected nozzles.

Thanks Mike, you actually gave me something to consider, gonna take a closer look at magenta damper to see if it's contaminated with yellow. BTW, test print same as before head soak, did not regain any nozzles, head soak was an attempt to clear two clogged black nozzles.

 

[Sign Works]

MikePro is correct. Also, it sounds like you could have a persistent cross-contamination problem. The fact that the blue you are printing is greenish tells me that yellow might be printing where magenta should be. Are you 100% sure that you got all of the magenta out of the yellow line? If so, it's possible that the head is damaged internally and/or the cap top is not draining properly.

Thanks VanderJ, will also double check pump lines for possible damage from crimping.

I do have another question, when manually raising the captops how do you know how far up you should go? 1-2 complete turns after captops come in contact with the print heads? Is there a general rule on this?

 

[equippaint]

I'd say cross contamination also. The 1 time we did a head soak we had it happen. Did just the black/cyan head and the black ink siphoned back into the cyan. We changed the ink cartridge then syringed the cyan until the black was out of it. Was a lot more than you'd think too.

 

[Sign Works]

Thank you to all that responded. Got it, there was yellow backed up into the magenta. It's odd that it was so hard to notice when printing blocks of magenta but how drastically it changed the blue. I was so frustrated that I didn't stop to think about basic color composition to determine the culprit, thanks again for pointing me in the right direction.