HP Latex 370 Printing Fine For A Few Inches Then Getting Fuzzy & Banded

I've been having issues with my HP Latex 370 for a little over a week now where my prints will look nice and crisp for the first few inches, and then suddenly my colors start to bleed into one another and become slightly darker around the edges, and also fuzzy and slightly banded through the whole print. Sometimes it prints for five inches before the print quality goes bad, sometimes it prints around two feet before it goes bad. I've been printing solid blocks of C, M, Y, K, LC, & LM as my test file, but nothing I do seems to work. The printer seems to be laying down a bit of debris in the area closest to the station–specifically little specks of black–but I also notice very small white areas where the vinyl is showing through. I thought this to be a printhead issue, but considering the prints start out nicely and then all colors go bad at the same time I am now unsure. I have taken out all printheads, removed all buildup from around the edges, ran the machine through several auto-cleanings, auto-aligned the printheads, calibrated substrate advancement, and just about everything I can think of. I noticed my maintenance cartridge had some black streaking across the cloth padding and some overspray down near the caps, but don't know if that's normal or related to the issue.

Hi @footlongwheat, It is strange that the issue is kind of intermittent and the printer is able to print fine for a few centimeters. About the maintenance cartridge, the black lines in the cloth are normal (pointed in red in the picture attached). A little bit of overspray near the caps could be normal as well but it should not be a big amount. I've been printing solid blocks of C, M, Y, K, LC, & LM as my test file, but nothing I do seems to work -> From this I understand that when printing the solid blocks you see the issue in all of the colors which should indicate that the issue is not specific for one of the lines. You also mentioned there is a little bit of debris in the printzone close to the SVS side, if after cleaning the area you see the debris again, it could be that some HW part is wearing out because of friction with another part. I suggest contacting your support representative to look into it. Another thing that could help to understand what is happening is confirming if the issue only happens with one media or if you are seeing it in different media. Remember that we recommend using HP certificate media with the OMS published in media locator. If it is only happening in one media, it could be that the media slips in the middle of printing. Depending on the media type we recommend printing with the media attached to the TUR. Also, you could run the Rewinder Calibration (this needs to be performed by a service engineer). If it is happening in different media, there could be some HW issues. We recommend contacting support to check the substrate path like the drive roller motor, drive roller encoder... What I can also think of is trying to print with the OMAS disabled to see if there is any difference. Another thing that could be checked by a service engineer is the cleaning roll advance, there is a test that helps check if the cleaning roll is advancing as expected. Maybe if the advance is not correct the printheads are not being correctly cleaned and the issue appears in the middle of printing. For this kind of issue is difficult to give a good assessment without more information, our main recommendation would be to contact support so they can perform some tests and have a better understanding of the issue.

Hi Daniela, Thanks for your help, I'll run through your suggestions and see if anything resolves my problem. Do you have a number for HP Latex support? Each time we call we reach the wrong department, and contacting HP is generally kind of a pain it seems. Thanks again, Aaron

Hi @footlongwheat, Have a look at this page: https://www.hp.com/us-en/printers/large-format/latex-printer-workflow-solutions-services.html. I do not have any other specific details.