Canon MP970 Service Manual page 13

Unsatisfactory print quality No printing, or no color ejected.
Paper feed problems (multi-feeding,
skewed feeding, no feeding).
Carriage movement problems (contact
to other parts, strange noise).
Faulty scanning (no scanning, strange
noise).
The CD / DVD tray is not pulled in the
feeder.
Printing is faint, or white lines appear
on printouts even after print head
cleaning.
Line(s) not included in the print data
appears on printouts.
Paper gets smeared.
- Examine the inside to confirm that no parts are damaged,
and the rollers are clean.
- Remove foreign material.
- Adjust the paper guide properly.
- Set the paper properly.
- Confirm the following:
- selected paper source
- attachment of the rear cover
- connection of each harness and the logic board
- sheet feeder unit operation
- Replace the
- sheet feeder unit,
- cassette unit, or
- logic board.
- Confirm that the carriage timing slit strip film is free from
damage or grease.
- Clean the carriage timing slit strip film (with ethanol and
lint-free paper).
- Remove foreign material.
- Replace the
- carriage timing slit strip film, or
- carriage unit.
- Confirm the connection between the scanning unit and
the logic board.
- Replace the
- scanning unit, or
- logic board.
- Confirm that the reflector of the CD / DVD tray is clean
and is free from any damages.
- Replace the
- CD / DVD tray, or
- logic board.
- Confirm that the orange tape is properly removed from an
ink tank, and the ink tanks are installed properly.
- Perform print head maintenance.
- Replace the
- ink tank,
*1
- print head .
- Remove foreign material from the purge unit caps, if any.
- Replace the
- purge unit, or
- logic board.
- Remove and re-install the print head.
- Confirm that the ink tanks are installed properly.
- Perform print head maintenance.
- Replace the
- ink tank, or
*1
- print head
.
- Perform the following:
- Automatic or manual print head alignment in the user
mode
- LF / Eject correction in the service mode
- Clean the paper feed rollers.
- Replace the
- purge unit, or
- logic board.
- Feed several sheets of paper.
- Perform bottom plate cleaning.
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