just refilled the black cartridge on my lexmark all inone centre,followed the instuctions the black ink levels are 100% on screen but it is not printing in black
take the cartridge off, touch a damp tissue / kitchen roll to the area the ink comes out of. don't rub it.
re-insert the cartridge
check the cartridge IS inserted corectly.
do a 'nozzle clean' from the printer properties page and do a 'nozzle test' / 'print test'
also some cartidges need a breather hole. check if yous has one and make sure it's clear.
I have a Lexmark 1180 and I have found that when refilling cartridges, the biggest problem is air getting in. Although this could be overcome eventually by sucking it out it became a real pain and I`ve given up refilling.