My Canon IP3000 printer developed problems printing. I purchased a new print head from Canon and installed it. I am still getting weak and incomplete patterns on the black ink. I think it may have something to do with a waste ink problem.
It will not complete a print head alignment, (because of not printing black), and printing documents is very incomplete in black. I have also replaced the black cartridge 3 times to eliminate the possibliilty of a faulty cartridge.
Help anyone?

You have no problem with the waste ink, your black nozzles are clogged. You have to clean them. The best way is with speciall nozzle cleaning solution, but if you cannot find any, try with hot water (a lot of hot water, but not too hot). Run 2-3 times cleaning cycle, and print a pattern each time. Leave the cartridge to rest for the night, and the next day print again the pattern. I think it should be better :)