Not printing - Flashing lights!!

If the following happens to your printer from canon's support page i found these:

"Issue: Power light (or Alarm and Power lights) alternate(s) between orange and green
Solution: The i350 may require repair


Unfortunately, the issue you describe seems to indicate that your product may require repair service. If you feel your product might require service, a Technical Support Representative will be happy to answer any questions you may have and explain the service options available to you. You can contact us through the email link or phone numbers listed below."

Everytime you do head cleaning, the waste ink goes into the waste ink pad which is a built-in feature inside the printer. Its function is to prevent these waste ink to spilll all over the other parts of the printer. When this pad becomes full, thats the time when the lights start to blink. This serves as a warning that this pad is already full. Contact your printer technician to replace this pad.

Sometimes you need to push the button on your printer and hold it for several seconds. My Canon ip4200 is this way when I change cartridges, esp. if I use refilled cartridges or another brand. Usually the light will go off after holding and it prints fine and acts normally.