Printing grainy in the middle of the print run

Hi everyone, Wonder if someone can help. I have HP Latex 335 and printing ok on but after around 200mm printing, it will become grainy. Anyone having the same issue as well. Note: Run all the test and alignment and been using the same material for years.

Hi @zarahyeats14065, Looking at the images, the problem seems to point to an issue with the PT printhead. During printing, the PH seems to stop firing Pretreatment or fires it in excess generating bleeding (the pimple you mention). Is the PH still under warranty for consumption and/or date? Try replacing the printhead and if the problem still appears the issue could point to air in the IDS tubes. In that case, please contact your support representative.

i have a 315 and its doing the same thing. ive replaced the print heads and no help. mine is getting worst and worst no matter what kind of media HP prime gloss CP is the worst.

here is a photo for the message above