My Canon I550 quit printing.

Hi tewsahn,
The waste ink "tank" is actually a set of felt pads under the path where the printhead carrige runs. One narrow strip pad is clearly visible along the centre of the path when the lid is openned and is easily removed, but the major absorbers are lower down. The pads could be cleaned and/or replaced with new but it is a very messy job (ink stains!) and requires the printer to be dismantled - not too difficult for a mechanically minded person and I did not experience any tricky reassembly realignment problems. After I finished this task, I eventually found the Service Manual at:
http://www.fixyourownprinter.com/reference/manuals/public/canon
If this process is carried out successfully you are advised to "reset the Canon i550 waste ink counter" (do a Google search - many guide postings), before continuing to use the printer again.

An alternative solution, if the printer is still responding, would be to open the printer case (separate the top and bottom halves), find and redirect the two waste ink drain hoses from the suction pump (located under the printhead parking area ) from going into the waste pads, into two extension hoses (that you must provide) and feed out through the back of the case into an external waste ink container - you will still need to reset the waste ink counter because the printer will eventually reach the full waste count. Do a Google search on "waste ink conversion/collection kits", associated with using "continuous flow ink systems"/(CISS) for more help.
See:
http://www.continuousink.info/forum/index.php
http://www.octoinkjet.co.uk/store
Here is a useful printer help reference:
http://www.weink.com/Support/html_whitepapers/index.html
Hope you are successful if you try this repair.
gp26, 21 Sept.2009

An error has occurred in the printer. The number of flashes indicates the type of error, as outlined below. Check the cause and take the appropriate action.
Two flashes: Out of paper or paper feed error
Replace the paper correctly and press the RESUME/CANCEL button.
Three flashes: Paper jam
If paper has jammed in the printer, clear the jam, replace the paper in the printer correctly and press the RESUME/CANCEL button.
SeeMy Canon I550 quit printing. - bullet.gifs
Four flashes: Empty ink tank
If you press the RESUME/CANCEL button, it will continue printing with an empty ink tank. However, when printing is finished, replace the ink tank immediately. If you continue printing with an empty ink tank, it will be a cause of troublMy Canon I550 quit printing. - bullet.gifSee Replacing an Ink Tank
Install a print head.
Eight flashes: Waste ink tank almost full
The printer has a built-in waste ink tank for the ink used during print head cleaning. Eight flashes indicates that the waste ink tank is nearly full. Press the RESUME/CANCEL button to cancel the error so yoMy Canon I550 quit printing. - i_note_us.gife printing. Before the waste ink tank becomes completely full, contact a Canon service representative.
NoteCanon recommends to call for service as soon as this error occurs. Once the waste ink tank becomes completely full, printing will no longer be possible.
POWER lamp flashes alternate green and orange:
An error that requires contacting a Canon service representative may have occurred.
Turn the printer off and unplug the printer from the power supply. Plug the printer back in and turn the printer back on.
If the problem remains, contact a Canon service representative.