Printing Problems - Canon FAXPHONE L75 Service Manual

Printing problems

• Faulty printing (Evaluation criteria: Test print is faulty.)
• The paper is not fed correctly. (Evaluation criteria: Look at the actual unit.)
The main motor does not run.
(1) Check the connection between the main motor and the PCNT board (J401).
(2) Check the main motor's resistance. 8.1 ~ 12.54 Ω/1 phase is normal.
(3) Replace the main motor.
(4) Replace the PCNT board.
(5) Replace the SCNT board.
The paper is not picked up from the auto sheet feeder.
(1) Check whether the recommended paper is used.
(2) Check whether more than 100 sheets of paper have been loaded in the auto sheet feeder.
(3) Check whether the paper has been loaded into the sheet feeder correctly.
(4) Check the connection between the paper pickup solenoid and the SCNT boatd (J9).
(5) Replace the paper pickup solenoid.
(6) Clean the separation pad.
(7) Replace the separation pad.
(8) Replace the separation pad spring or the lifting spring.
(9) Replace the SCNT board.
The paper skews.
(1) Check whether the recommended paper is used.
(2) Check whether more than 100 sheets of paper have been loaded in the sheet feeder.
(3) Check whether the paper has been loaded into the sheet feeder correctly.
(4) Check whether dust or paper debris have built up inside the auto sheet feeder.
(5) Check whether the paper pickup roller, or any other rollers, are damaged or scratched.
• The printing operation is abnormal.
The unit indicates there is a paper jam when there is no paper jam.
(1) Check the connection from the paper edge sensor to the SCNT board (J14).
(2) Check whether the paper edge sensor and actuator and the paper eject sensor actuator are in their correct positions.
(3) In test mode check whether the paper edge sensor and the paper eject sensor are operating correctly.
(4) Replace the SCNT board.
4
Main motor connector
1-2 : 8.1~12.54Ω
3-4 : 8.1~12.54Ω
Main motor
1
4
1
Document feed motor connector
1-2 : 13.95~25.68Ω
3-4 : 13.95~25.68Ω
11
To document feed motor