790 plotter image quality problem

[akbareshghi]

My quality images intermittently become bad but I don;t know the cause or causes of this quality problem(my machine HP T790 plotter)
I guess because of following causes but please introduce me about troubleshooting this problem.
1- cloging and entering air into the plotter heads(vaccum problems)
2- use old charge ink bottle for more than 2 years
3- misconfiguring paper weight 170 gram china coated paper into heavy coated paper on the panel or because of bad paper quality
4- other causes


thanks a lot for your suggestion and solutions described
please introduce and explain your solutions01.jpg02.jpg03.jpg04.jpg05.jpg

[Elmtech]

Re: 790 plotter image quality problem

I would start by fitting a set of genuine inks and purging the ink tubes. Next I would try the print heads.

[akbareshghi]

Re: 790 plotter image quality problem

test quality is good on plain paper but when i printed one templated full color large size on the coated ,then image quality go bad
please help me

[Kiran Otter]

Re: 790 plotter image quality problem

Contact whoever makes your 3rd party inks and ask them why that is. Otherwise, put in genuine HP ink cartridges, purge the old ink from the tubes, and start from there.

Kiran

[theengel]

Re: 790 plotter image quality problem

Your yellow is dropping out. You probably have air in the lines and/or printhead. Also, probably contaminated ink in several colors.