I have an Officejet Pro 8500 Wireless printer, which is only using one colour (magenta) for printing. Therefore I cannot print anything which uses black print, ie most printing. This has just happened recently. I have cleaned the print head a number of times, with no change. When I attempt to align the print head, I get a message: "Alignment Failed - consult user documentation", but I cannot find anything in the documentation which refers to this problem. What can I do to rectify? Thanks!