Epson 740 color quit

Our Epson Stylus 740 suddenly quit printing color. The indicator shows about half of the color ink left. When I have it to print its test, the black diagonal lines print with a few breaks. The color lines don't print, and it prints "W12788 102382", which I don't think it should print. Some times it prints a tiny amount of the second color in the test. This happened immediately after I printed a page that jammed in one corner. When I pulled it out the page, black ink was smeared on that corner.

I did all of the nozzle check, clean and alignment. I checked to see if the color cartridge was seated properly. I put the printer on a different computer, and it still has the same problem.

How can I fix this?