I have a canon pixma iP 1600 which I only use infrequently. When I print a nozzle test I get red (more pink) and yellow but no blue. Ink level is OK and I've tried deep nozzle cleaning many times without success. I guess that there's a blockage but can it be cleared?
the "nozzle check page" is a single command sent to printer firmware. If really no cyan (blue) is printed, there is really a printer problem - either no ink or clogged nozzles.