HP Photosmart 7520 won't print black color. I have tried all of the"fixes" that HP recommended. It still doesn't print black. The color worked but it was poor quality/blurred. I cleaned the print head but it didn't fix it. The printer shows that it needs head alignment. I installed a new print head but that didn't help. The printer still shows that it needs head alignment. Any thoughts on how to repair this? Thanks, Mike H.