I have a Dell Computer with a Windows XP operating system. A few days ago I refilled my black Lexmark print cartridge. I use only this cartridge as I have no use for a color cartridge. I have a Lexmark 510 Series Printer. I have not experienced any difficulty using my printer previously as it has been quite reliable. When I loaded the black 16 print cartridge this time I could not get it the printer to operate. I finally got the printer to work after I added the blank color cartridge which I have not used for many years. The problem I am having now is that although the printer works, the document that is printed contains no printed material, only a completely blank document. I can't recall this ever happening previously. The printer is showing me that it contains a completely full black cartridge as it always has previously. I have tried a few times to print a document but the document contains no printer material. Please help. BVR