Awful black letters

[zibizibi]

Hi,

I've got a Canon MP640 ink since 10 months. Recently it started printing like this : http://uppix.net/6/b/b/5115d3074481f07d81a96f3b02658.jpg

I ran all cleaning/fixing programs available in the printer, I changed the 2 black cartridges (small and big ones), no result.

What could cause this problem and how to fix it ?

 

[hang-the-9]

Should be in warranty, replace it. Looks like the print heads are bad.

 

[zibizibi]

I had run the cleaning programs before changing the black cartridges. Then I printed this page. Now, I ran the cleaning program again and the printing is now OK.

Weird 😵