Canon MP970 Service Manual page 14

Faulty scanning
The back side of paper gets smeared.
A part of a line is missing on printouts. - Perform nozzle check pattern printing, and confirm that
Color hue is incorrect.
Printing is incorrect.
No ejection of black ink.
Graphic or text is enlarged on printouts. When enlarged in the carriage movement direction:
No scanning.
Streaks or smears on the scanned
image.
- Clean the paper path with a cotton swab or cloth.
- Clean the paper feed rollers.
- Clean the platen rib (clean the paper path with a cotton
swab or cloth).
- Confirm that the platen ink absorber fits in place
properly.
- Confirm that the paper eject rollers are free from ink
smear.
ink is properly ejected from all the nozzles.
- Replace the
- ink tank, or
*1
- print head .
- Confirm that the ink tanks are installed properly.
- Perform print head maintenance.
- Replace the
- ink tank, or
*1
- print head
- Perform print head alignment.
Replace the logic board.
- Confirm that the ink tanks are installed properly.
- Perform print head maintenance.
- Replace the
- ink tank, or
*1
- print head .
- Remove foreign material from the purge unit caps, if any.
- Replace the purge unit.
- Clean grease or oil off the timing slit strip film.
- Replace the
- timing slit strip film,
- carriage unit,
- logic board, or
- scanning unit (when copying)
When enlarged in the paper feed direction:
- Clean grease or oil off the timing slit disk film or the
timing slit disk eject film.
- Replace the
- timing slit disk film,
- timing slit disk eject film,
- timing sensor unit,
- LF roller,
- platen unit,
- logic board, or
- scanning unit (when copying)
- Confirm the connection between the scanning unit and
the logic board.
- Replace the
- scanning unit, or
- logic board.
- Confirm that the driver software is installed properly.
- Confirm that the USB cable is connected properly.
- Confirm the light of the FAU lamp.
- Clean the platen glass.
- Confirm the connection between the scanning unit and
the logic board.
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