When printing black text there are streaks of missing ink - horizontal in portrait, vertical in landscape.
A nozzle check pattern is perfect - the PGBK bars are solid and the pattern is complete.
Printing the same files to a laserjet gives perfect text. Making a copy of this text on the MG7550 gives the same streaky result.
Nozzles have been cleaned and deep cleaned - but the nozzle check pattern does not show any blocked nozzles.
The printer is less than one year old.
What might be the problem?