I had a 700ml LM cart fail in my 9890. Had LM ink all over the floor. I did not have any pressure sensor errors, but definitely the cart is leaking from the bottom edge of the cart where it is assembled together. Contacted Wells at customer service, her promptly sent me a new cart along with some ink to replace that had leaked all over the floor. Thank You for the great service. after refilling/priming the new cart with LM ink. I went to make a print and it was way off color. did a test print and the LM channel was not printing at all. no lines what so ever. so i did a standard cleaning of pairs to prime the line with ink thinking there was an air bubble to move. after doing this over several days as i did not want to overheat the print head. there was no improvement in getting ink to the print head. I checked the lines and thought i saw air bubbles. but wasn’t sure at first if ink was flowing at all through the line. although the ink cart was going empty from doing several initial fills, i figured ink was flowing and no air was seen in the lines. I couldn’t see any visible damage to the damper unit, but I figured it was worth a shot to replace since so much of it is just thin foil, took the assumption that maybe the damper or this foil was just sucking air. After replacing the damper assembly, still no printing from the head. I took the lines off the damper unit and also from the back of the cartridge unit and flushed the lines out clear. no ink, no flush, completely empty. I then reconnected and observed during the initial fill the ink flowing clear to the print head. all should be golden i felt. but still not print test working. I have come to the conclusion that the 700ml cart failure also caused my head to fail. could the pressure change from the cart cracking and leaking caused the head to collapse.? I’m to the point now of actually removing the head and trying to back flow flush through it to see if there was something sent through the lines causing just a clog. but i feel that the head has failed and will be just replacing it. any experience regarding cartridge failure causing head failure is wanted. also any great sources for purchasing a print head. I found one on a chinese site for 1550 about and a 2 year warranty… I have requested a copy of their warranty to review.