Drazen had it right in my opinion. I always look at the data cables going to the carriage. Ususally a grounding issue with the ZIF ribbon cables. Throws random artifacts into the print (banding or patterning) I hear about this from printers that take electrical hits or browns. (Lighting or power outages). Most Latex printers are bulletproof from day one. A few dogs out there, always solvable. These are pretty simple machines really. All of the subsystems are replaced as assemblies.so even crappy technicians such as myself can fix one...eventually.