i just solved my issue. i changed the artboard from cmyk to rgb then i changed the black in illustrator to a spot color black and turned the values in rgb to zero for the spot color. turn the intensity & contrast all the way up in your printer settin...
did you figure out what was wrong? im having the same issues. it prints a very light blue on transparancies all of a sudden. i manually cleaned the print head too and still no luck.
