How to diagnose and fix poor quality HP OfficeJet Pro 8025?

A picture is perhaps the best explanation. The picture below shows the Powerpoint and resulting print. Can anyone help on what to do? Observations: Blue and yellow did not print at all Magenta printed but looks pink. Magenta looked good (no small lines). Black looked good, but then went bad. Magenta AND black are large stripes. The pitch of the stripes looks the same between them but the duty cycle is different. Things done before this print removed cartridges, placed damp paper towel in the trough under the carriage. Moved carriage back and forth with multiple towels. did alignment. It failed

Question by Robert Lugg on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.