what is this (in the nozzle check pattern)?

[ikolt]

Dear all,
yesterday I have noticed a weak streak (in the GY channel) in the nozzle check pattern (2017.12.06). The regular cleaning procedure did not help. Three weeks ago (2017.11.15) there was a similar (but more pronounced) problem in the CO/MBK channel. That time the regular cleaning did not help either (actually, the streaks became even stronger after the cleaning). However, as I have replaced the set of cartridges the nozzle check pattern became immediately OK. Since that time I did not change the cartridges. Yesterday I have also tried to replace the current GY cartridge to the one from a previous set (fully refilled). However, this did not help.
Note, I see the problem only in the nozzle check pattern; I do not see anything suspicious yet in the printed images. How do you think, what is the cause of the problem? I use the original cartridges (2 sets) refilled with PC inks. I have refilled the cartridges many times in the past and everything worked fine. Should I buy a new original carts set (assuming something went wrong with my 3rd party inks)? Should I try deep cleaning (I am a little bit concerned to avoid damaging of the print head)? I own my Pro10 printer for exactly 1 year (yesterday the warranty period expired). The last 2 months I do not print much but at least I print the nozzle check every 2-3 days.
Thanks!

 

[mikling]

One of the reasons of the paddles inside the cart is that ink needs to be continually stirred up. Nozzle checks do not move enough ink to redistribute what is inside the printhead itself. Like the MBK that preceded the same symptoms, it will eventually go away with some more printing. I've seen this occur numerous times to myself and it has always gone away with more printing. It is possibly due to the ink settling or uneven feed across the nozzles or some air inside the chambers preventing the ink inside the backchamber from creating uniform backpressure when the nozzles are firing. For me it eventually goes away and you don't see it in the the images as the nozzles are nor normally firing in a uniform pattern at the same time.

 

[The Hat]

yesterday I have noticed a weak streak (in the GY channel) in the nozzle check pattern

Try running the Ink Quality Maintenance before you start, it will help to freshen the ink before you print the nozzle check, also lay off the unnecessary cleaning, it is only wasting you ink...

 

[ikolt]

Thanks guys for your advice! I also thought that the Ink Quality Maintenance could help, but unfortunately it didn't. Yesterday I have printed 17 photocards (10x15cm) - all are ok. The nozzle check after the printing still shows that weak streak, but it seems to be weaker now (difficult to say). Will try to print more next weeks and will report you if there will be any changes.