Grainy prints

[tamif]

I have started having problems with my prints coming out grainy. It seems like dark blue is the worse. I have had prints that were real nice and then the next one is grainy again and some that the yellow prints fine but the blue part is grainy. After reading up on it I have checked to make sure the temp and humidity is good in the office, I have cleaned all print heads and aligned all print heads. I've printed the optimizer print test (optimizer might need a slight adjustment, but not much.) I have done the force drop detection test. All of the numbers are below 25. If I remember right that was an acceptable number and my printer control page says my printheads are good. I have attached pictures of the printhead test images. I have also noticed that while doing all of these test there is always a problem printing the color calibration test. Every time I send it to print it stops and gives me the error 79:04. I am printing with an HP 315 Latex printer on HP Prime Gloss GP vinyl with original HP ink.

 

[balstestrat]

So lets see a picture of the issue first.

It can usually be two things. Either one or more of your heads is starting to wear out and needs replacing.
Or you have a bad roll with plasticizer migration which will result to a kind of white spotty print. It might look like grain. How old is your roll?

For the 79:04, update your firmware if you are not running the latest version NEXUS_07_09_00.1.

 

[tamif]

So lets see a picture of the issue first.

It can usually be two things. Either one or more of your heads is starting to wear out and needs replacing.
Or you have a bad roll with plasticizer migration which will result to a kind of white spotty print. It might look like grain. How old is your roll?

For the 79:04, update your firmware if you are not running the latest version NEXUS_07_09_00.1.

The roll is brand new. I tried wiping the material with alcohol and printing on it after reading that it could be the vinyl. It didn't seem to make a difference. Should I just replace heads with the blue in them since all my sensors say they are all good and the test print showed all of them looking spotty? I am attaching a picture of what it should be and what it is so you can see the difference. Thank you for your help.

 

[balstestrat]

If it prints sometimes just fine and sometimes like that, I bet you have issue with the material.
The heads don't print just fine today and like crap tomorrow. If they go bad you won't get any good ones out after that.

Your test nozzle check print looks just fine. It's supposed to look like that.

 

[tamif]

Ok, I thought the test prints looked bad because they were all splotchy. I figured they would print smooth like regular prints. I have only had one time where the blue printed better and it was just after cleaning the printheads, by the end of the print it was going back to grainy. Other colors seem to print good, so I went ahead and ordered and black/cyan printhead. The machine uses two of them so I don't know if replacing one will do me any good. I do have some new vinyl coming so I will try that as soon as it gets here. Thank you so much for all of your help.

 

[balstestrat]

If the heads are equally as old just change both.

 

[tamif]

Would this printhead be the one that is not working right? It looks a little different from the others.

 

[balstestrat]

That's your light cm head. Seems normal.
I don't think it's using it for that dark blue sample of yours.

 

[tamif]

Thank you. I appreciate your help.