Test print OK with print quality set at best, but has horzontal white bars when set at normal & fast

[A4Skyhawk]

I have followed all the troubleshooting steps provided by HP at their website, including cleaning the non-removable print head and the cartridge soak.  My OS is Ubuntu 16.04 LTS.  The printer software is HPLIP hpcups 3.16.3, which has an HP Toolbox in which I can set the print quality at fast draft, normal, best, and high resolution photo. 

The first 3 photos shown below are of a test page from the HP Toolbox, and the last 2 are printouts selected from the printer's touch screen.  As can be seen from the first 3, print quality when set to best looks ok, but fast draft and normal have white horizontral bars.  Does this suggest to anyone what might be the cause of the problem and how to fix it?  TIA.

BestFast DraftNormalPrint Quality DiagnosticPrinter Status Report

[A4Skyhawk · Accepted solution]

02-15-2018 10:40 AM - edited ‎02-15-2018 10:59 AM

I have solved my problem of streaking black printouts.  Firstly, I tried the HP recommended fixes and they did not solve the problem - immediately.  By the time that I had tried these fixes (I use my printer only a couple times per month and for small jobs), the nozzle on the black cartridge had dried.  So I continued using the alcohol/warm water soaking until it looked like this should no longer be the problem.  However, the printouts still were streaky (the sreaking in "best" was very faint, and worse in the other modes).  I then continued with flushing the printhead ports with warm water and a syringe bulb until the paper towel on the under-side (the printhead is not removable) showed no ink when flushing.  I also changed my print quality setting from "fast draft" (up to now, my default setting) to "best".  This setting is used in the "test page" print out, too.  Eventually, the test pages in "best" mode cleared up, and when I checked the "normal" and "fast draft" they, too, were free of streaks.  Everything is back to normal now, and I returned to the quality setting of "fast draft" mode.  However, to prevent problems from dying ink, I now print the HP test page in all three modes every 2 weeks.  It has been about 2 months since this probem was resolved and, so far, it has not returned. 

HTH,

A4Skyhawk