Canon MP640 Service Manual page 18

Faulty scanning
*1: Replace the print head only after the print head deep cleaning is performed 2 times, and when the problem persists.
*2: Only for CD / DVD printing supported regions.
The back side of paper gets
smeared.
Graphic or text is enlarged on
printouts in the carriage movement
direction.
Graphic or text is enlarged on
printouts in the paper feed direction.
Streaks or smears on the printed
CD / DVD.
No scanning.
Streaks or smears on the scanned
image.
<2. LIST OF ERROR DISPLAY / TROUBLESHOOTING>
(3) Perform paper feed roller cleaning.
(5) Replace the following item(s):
- Pressure roller unit (if smearing is heavy)
*1
- Print head (when smearing is caused by the print head)
(1) Clean the inside of the machine.
(2) Perform bottom plate cleaning.
(3) Examine the platen ink absorber.
(4) Examine the paper eject roller.
(5) Replace the following item(s):
- The part in the paper path causing the smearing
(1) Confirm that the carriage slit film is free from smearing or
scratches:
- Cleaning of the timing slit film.
(2) Replace the following item(s):
- Timing slit film
- Carriage unit
- Logic board
- Scanner unit (for copying)
(1) Confirm that the LF / EJ slit film is free from smearing or
scratches:
- Cleaning of the LF / EJ slit film..
(2) Replace the following item(s):
- LF / EJ slit film
- LF / EJ timing sensor unit
- Platen unit
- Logic board
- Scanner unit (for copying)
(1) Confirm that the CD or DVD is a recommended one or not,
and change the printer driver settings accordingly.
(2) Replace the following item(s):
- CD-R tray
- Pressure roller unit (if smearing is heavy)
- Platen unit
(1) Replace the following item(s):
- Scanner unit
- Logic board
(1) Clean the platen glass and the document pressure sheet.
(2) Confirm the position of the document pressure sheet.
(3) Replace the following item(s):
- Scanner unit
- Document pressure sheet
- Logic board
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