Missing section when printing nozzle check

[Kompyused]

This printer came out in 2018. Wf 7710. So its 5 years old. With original ink still in them except for black which dried up and was the only one empty. What action can I make to recover the missing row?

 

[Ink stained Fingers]

This printer came out in 2018. Wf 7710.

Bu what was the actual purchasing date ? There is somewhere an Epson service internet page on which you can check the warranty status by serial number.

What action can I make to recover the missing row?

I would try another flushing action to clear the black channel but I wouldn't know how to proceed from there if that doesn't work.

 

[James Mike]

Not an epson person but prolonged soaking seems to help: