Canon Pixma MP520 black printing problem

[rickdiamond]

I have a Canon Pixma MP520 inkjety printer that prints fine in color but leaves white streaks in black. Following is a description of the problem and what I've tried, copied from wha tI sent to Canon email support. They said, “Based on the troubleshooting you have done, the unit would require service,” but they didn't indicate what kind of service. Any ideas?

Connection: USB
Operating Systems: Windows Vista
Problem Type: Poor Image

Please provide the exact problem description
(Please do not enter any credit card details or other financial
information):
Poor quality printing or copying black. Many horizontal strips of
either white space or very light print in between the other strips that
are OK.

Please provide previous troubleshooting steps, or information that can
help Canon assist you:
1. I replaced the black ink cartridge. It had shown "ink running low"
for some time and I figured that was the problem. However it was still
bad after replacing.
2. I cleaned the print heads. No improvement.
3. I cleaned the print heads again. No improvement.
4. I deep cleaned the print heads. No improvement.
5. I put in another new ink cartridge, thinking the other may have been
defective. No improvement.

Has anything changed since the unit functioned properly?
(Installation of software, setting, cabling etc.):
No. Note: The ink cartridges I use are not Canon, but Staples
remanufactured" cartridges. I have been using these for some time with
no problem. I considered trying a Canon cartridge to see if that solved
the problem, but thought I'd check with you for ideas before trying
that. I'd hate to end up with three open cartridges with none of them
working. Any suggestions?

Are you receiving a specific error code, if so please enter here:
No. Thanks for any help you can provide.

 

[aoife]

It seems like the printhead is having a problem, cleaning won't help anything. I think you might have to send it in for a service.