I am sorry for posting in this old thread but I just saw a great solution for this problem in a tech support site. It seems like you can easily clean it without working to hard... here is the page for the solution - Can't print in Black ink
Hope it will help
Good luck
mary
Hi, I had some problem with my HP printer myself but luckily I found a great new tech support site that helps you fix almost every product. They also have live chat support that you can use for free.
Here is the page for HP Support
Good luck
Marcella
Hi,
I never heard about this error but one time my printer did some funny noises and I turned to a tech support site that help me solve it. I am positive you can find some answers there.
Here is the page for Canon i850 Support
hope it helps
Marcella