Epson 7800 Suddenly Has Bad Nozzle Check...Again

While I was working on color correction for a festival print in April my Epson 7800 was printing fine, until it suddenly wasn’t. It went from perfect nozzle check patterns to almost no nozzle check pattern instantly. I approached it as a clogged print head problem for weeks, and then suspected that wasn’t the problem. I replaced the air pressure pump assembly in the back of the machine. Bingo! Printed great again right away! For about 2 weeks. Then it did the same thing again. I got up one morning, printed a nozzle check that looked fine, printed a couple of prints just fine, and then it suddenly printed almost no ink. Did another nozzle check, which was almost nonexistent. I have soaked the head a couple of times on a paper towel with cleaning solution, and in the meantime, nozzle checks have improved to 5 colors looking O.K. and 3 only half printing with the same pattern missing every time. I’ve read that such an identical pattern indicates a compromised print head. The missing pattern is the same on each nozzle check. I don’t see how the print head could have been compromised so suddenly, from one print to the next. The air pressure pump assembly must still be working (I replaced with a used part, so that’s iffy) because 5 of the colors check out O.K. Only Black, Cyan, and Light black are missing chunks. What should I be looking into next? Should I replace the Vacuum Pump? Should I persist in treating it as a clogged print head? Is it time to wave the dead chicken over it? If this sounds familiar to anyone, I would really appreciate some input! Thanks! ~ New Orleans Artist MOUSIE

THis indicates full dampers and maybe bad head.


Thank you… I’ll try replacing the dampers and cross my fingers about the print head. I’ve been using this machine for 17 years and I’ve never replaced the dampers!~ MOUSIE