I believe I may have finally developed a recovery solution for this type of print quality issues. I believe over time the ink out gasses and that gas is trapped inside the printheads (this issue dates back to the HP 10/11/12 printheads). Eventually the issue will get worse and then segments will completely be lost across the pagewide print bar. I worked at HP for 8 years and it's very sad that they seem to ignore this long standing issue (it wasn't a show stopper back when you could replace the printheads in the printers with the ink delivery system geometry that traps the gas).
I'm going to try to post more information on this solution but HP doesn't allow me to plug a solution but it's even hard to offer this solution to their customers for free via this forum. It requires a special tool that enables high pressure repriming of the print head while the gas is pushed out. For now I will try to get people the information via email and I hope HP allows this so their customers can be helped with this issue that has been reported many times on this forum (anyone with Pro X or Pagewide print quality issues such as the 1st page having some dropping, a waterfall effect, partially to fully dropped head segments just write to me at kenmaruska2 via the reverse of liamg .com have to be cryptic). I can't send this tool to anyone via this forum so hopefully the HP police allow this communication to happen - I'm helping customers so let this be OK.
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