Canon PIXMA MP750, Service Manual

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Symptom Solution Remarks
The paper is not picked up
from the auto sheet feeder. (1) Check the foreign matter in
the paper feed section.
(2) Check the connection
SHEET FEED UNIT to the
SPCNT board ass’y (JPM1).
(3) Replace the SHEET FEED
UNIT.
(4) Replace SPCNT board
ass’y.
The carriage motor does not
run. (1) Check the connection from
the SHEET FEED unit to the
SPCNT board ass’y (JPM1).
(2) Replace the SHEET FEED
unit.
(3) Replace the SPCNT board
ass’y.
Printing
problems
Carriage error
(The carriage comes into
contact with the push-on
plates at the left and right
sides, resulting in noise.)
(1) Check if grease adheres to
the carriage encoder film.
(2) Using lint-free paper
impregnated with alcohol,
wipe the carriage encoder film
with care so as not to scratch
the film.
(3) If a lot of grease adheres to
the carriage, replace the
carriage board because grease
might be spread to the sensor
on the carriage board.
(4) Replace the carriage
encoder film.
Printing
Quality
error • The printer does not at all.
• Printing stops midway.
• Certain colors are not
printed.
(1) Remove the print head and
re-install it.
(2) Carry out nozzle cleaning
on the print head five times
with the cleaning operation,
than visually cheek the test
print for non-discharge of ink
from
nozzle. ( Fig. 1-2)
(3) Remove and reinstall the
print head.
(4) Replace the appropriate ink
tank.
(5) Replace the print head.
(6) Replace the SPCNT board
ass’y.
(7) Replace the purge unit.