Canon i550 missing blue bars please help.

[Jon]

Hi there,

I have a Canon i550 with missing blue bars in nozzle check print out, (see below) ive reinstalled drivers, changed printer cables, and tried soaking the heads on damp tissue in a plate. Nothing has worked.... All other colours are perfect, and there is not a hint of blue in the blank areas.

 

[Grandad35]

Nozzle check patterns where complete blocks of nozzles are missing are usually electrical in nature here are a few of many posts on this subject:
http://www.nifty-stuff.com/forum/viewtopic.php?pid=14584#p14584
http://www.nifty-stuff.com/forum/viewtopic.php?pid=14076#p14076

You might want to try this - it is possible that an error causes the printer to "turn off" banks of nozzles when it senses a problem.
http://www.nifty-stuff.com/forum/viewtopic.php?pid=16110#p16110

 

[Jon]

Is there one of those, holding down resume and power twice until flash, type fixes for this problem?

 

[Grandad35]

Is there one of those, holding down resume and power twice until flash, type fixes for this problem?

This post describes how to reset the EEPROM on older Canon printers - I'm not sure if it works on your printer. Also, the incident reported in the link (where am EEPROM reset fixed a similar "missing bar" problem) has not been verified, but it's worth a try before buying a new print head (which also isn't a guaranteed fix).