Canon i 850 User Manual page 82

Routine Maintenance
After print head deep cleaning finishes, print the nozzle check pattern to verify that the head
is clean. If not, check that there are sufficient ink levels in all ink tanks before turning off
printer. Be sure to perform another print head deep cleaning 24 hours after turning off
printer. If the head is still not clean, the print head may be worn out. Contact a Canon
service representative.
Printing the Nozzle Check Pattern
Print Head Deep Cleaning 82