Thank you very much for the advice. All cartridges are original and not refilled.
You can soak in demineralized water but there is no need unless your water is contaminated with something bad and you would not wash with it. If your water is "hard" - lots of minerals - then the last flush is recommended to be with demineralized water.First bath your printhead a night in demineralised water (the one they sell for irons in every supermarket) with a drop of dishwashing liquid (Dreft/Fairy or alike).
There could be ink flow issues with cartridges. Clogged print heads happens as well. It is the dreaded electrical failure that permanently causes a print head to malfunction that we all worry about (not to mention the stray clogged nozzles that can lead to burning out those nozzles).Can the cartridges dry out or is it a clogged print head?
Since you are trying to diagnose what is at fault for the missing ink in the nozzle check, you should only use new cartridges or used but known working cartridges. This way you take the question of cartridge failure out of the equation and can then focus on the print head and/or logic assay board issues.Can I remove cartridges and then insert used ones or can I only replace old ones with new ones.