PIXMA iP8720 Printer Misalignment

[PaulCarlson]

I have a Pixma iP8720, which we purchased to create photo quality printouts. It's worked well, not used very often, for several years. Now we've moved, and unpacked it.
Everything works, except, the big PGBK print head is not aligned. Upon testing, it produces a "choppy" pattern instead of a solid block of black, and instead of a fine grid, the vertical lines bow outward. The other colors and gray are fine.
I have tried everything. The manual print head alignment does not help. Using different printer driver software does not help. Cleaning the print heads, even removing the tray to carefully wash it, does not help.
Is there any other possibility, anything else to attempt?
Thanks, Paul Carlson

[Patrick]

Hi Paul Carlson,

Blurry printing can be caused when the encoder/timing strip inside your PIXMA iP8720 is smudged. Cleaning this will resolve the issue.

To clean the encoder/timing strip, please follow the steps in this Knowledgebase Article:

https://support.usa.canon.com/kb/index?page=content&id=ART171023

If the issue persists, your PIXMA iP8720 would require service. You are eligible for Canon's Upgrade Program. This is for out of warranty units which have been diagnosed to require service, or for some reason are incompatible with a new or upgraded system. This option allows you a one-time opportunity to purchase a replacement product, discounted from the list price.

If you would like to take part in this option, please call our Sales Department at (866) 443-8002 Monday through Saturday, 9am to 9pm. Let them know you have been working with technical support and the Canon Upgrade Program was offered.

[PaulCarlson]

Thanks!
I was able to do the cleaning, but to no avail.
When I print a b/w double-spaced test document, about every second line is blurred out.
Time for the next step, it seems.
-Paul Carlson