PIXMA TS6420a double vision printing

[1hsmom]

I have a ts6420a and the printer is printing double words (on top of each other but just off enough to create a visual nightmare). I have cleaned everything, aligned the printheads etc. It will be both pages if I print double sided but If I print one page at a time sometimes part of the words are normal and sections are blurry and double. 

I've only had this printer 9 months. Help me fix this please. 

Does anyone know what else I can do? 

[Patrick]

Hi 1hsmom,

Blurry printing from your PIXMA TS6420a can be caused by a smudge on the encoder/timing strip.

Please follow the steps in this Knowledgebase Article to clean the encoder/timing strip:

https://support.usa.canon.com/kb/index?page=content&id=ART177605

[1hsmom]

we didn't see anything on the strip but cleaned it anyway and reran all the test pages which print perfectly. Still, whenever anything is sent to the printer it prints double. 

[rclark041]

I have the same problem but only with PDF files. I don't know why only PDF files. Is there something different about PDF files?