I am having trouble with my HP V40 all-in-one. First we noticed the black ink was looking gray. I aligned and cleaned the cartridges. This did not help. I checked the cartridges to make sure they weren't running out of ink. (The color prints fine). Then we were sent a fax that did not print at all. The fax machine went through the motions, but a blank page came out. I followed the troubleshooting instructions that I got on the HP website, but none of that found the problem. HELP!!