Canon MX860 Service Manual page 60

4-5. Special Notes on Servicing
(1) Print head problem (smeared printing, uneven printing, non-ejection of ink, etc.)
For problems that are supposed to be caused by the print head (smeared printing, uneven printing, or non-ejection of ink, etc.),
print the nozzle check pattern in the user mode to determine whether the print head is faulty or not.
< Procedures >
1) In the user mode, print the nozzle check pattern.
2) If there is a missing portion in the printed pattern, perform the print head cleaning (2 times at the maximum), and print the
nozzle check pattern again (in the user mode).
3) If the problem persists even after the print head cleaning is performed 2 times, perform the print head deep cleaning, then print
the nozzle check pattern again (in the user mode).
4) If the problem is still not resolved, i) turn off the machine and leave it for 24 hours or longer, ii) perform the print head
cleaning, and iii) print the nozzle check pattern again (in the user mode).
(2) Paper feed motor adjustment
1) When attaching the motor, fasten the screws so that the belt is properly stretched (in the direction indicated by the blue arrow in
the photo below).
2) After replacement, be sure to perform the service test print, and confirm that no strange noise o
gear, or out-of-phase motor, etc.) occurs.
The screws securing the paper feed motor may be loosened only at replacement of the paper feed motor
unit. DO NOT loosen them in other cases.
r faulty print operation (due to dislocation of the belt or
57 / 64