We have an acuity and love it. Fuji support not so much. We periodically run into banding and it has always been one of three issues (Assuming your nozzle checks look good and you haven't had a crash of some sort).
1. Media. Believe it or not sometimes the media itself causes the bands, especially cheap PVC. Print the same file on something simple like poster paper to rule this out.
2. A print head has been dislodged. It's remarkably easy to push a print head up a little when cleaning nozzles or if you hit something with the print head. They're only anchored on one side which seems crazy to me. Take the cover off the print head and push gently but firmly at the base of the print heads with something non-conductive. This is a pretty delicate operation in a rather tight space. It's really easy to do damage to the print heads. We've have to do it every 3-6 months for whatever reason.
3. UV lamps are old. As the lamps age, they cure inconsistently. More frustrating is that the banding isn't present in all prints or on all media. Fuji was REALLY bad at diagnosing this problem the first time it occurred here. It took a week of hair pulling and a third tech interview before they came up with it. With the relative paltry experience we now have it seems painfully obvious. At any rate, this can begin to occur as early as 500 hours.
