Pixma MG3650S - Vertical lines not quite straight

[Outback]

I have an MG 3650s canon printer and it has started to print vertical lines that are sort of zig-zag. I have done both the automatic ( no change) and manual head alignment ( a little better but not perfect yet) . The slight offset of print is enough for the Post Office to fail to read the QR/Bar Codes it prints out.
Do I need to keep doing a manual alignment until all is ok or is there something else to try ?
The attachment shows the lines, the top is after manual realignment.
Thanks.

 

[Mike7751]

Outback, I have exactly the same problem with my Canon Pixma MG7751.
Have you solved this problem?
What did you do?
Thanks - Mike

 

[Outback]

'Evening Mike,
it was all my own fault. I had refilled the Canon cartridge too many times, not realising that it also contained the printheads and these were worn. A new, original Canon cartridge and all was fine. It was as simple as that.
Cheers
Brian.

 

[Mike7751]

Brian,
Thank you - unfortunately the print head on mine is a separate unit - I've had the printer for nearly 6 years now so perhaps it's worn and needs replacing.
Best wishes - Mike.