Canon MultiPASS C50 Service Manual page 147

4.3.3 Scanning problem
• Faulty scanning (Evaluation criteria: Test print is good, but the copied image is
no good.)
• The document is not fed.
The document feed motor does not run. (Evaluation criteria: Check it visually.)
(1) Check the connection from the document feed motor to the PCNT board (J9).
(2) Check the document feed motor's resistance. 37 Ω/1 phase is normal. ( Fig. 3-13 )
(3) Replace the document feed motor.
(4) Replace the PCNT board.
(5) Replace the SCNT board.
The document slips against the rollers. (Evaluation criteria: Check it visually.
Stretched copy image.)
(1) See page 3-4 and clean the document reading section.
(2) Replace the reading section's rollers.
The document does not separate. (Evaluation criteria: Check it visually.)
(1) Check whether the reading motor is driving all the rollers. (Check for any damaged gears or
foreign matter stuck inside.)
(2) See page 3-4 and clean the separation roller and separation guide.
(3) Replace the separation roller and separation guide.
Faulty scanner unit's sensors (Evaluation criteria: The placed document or
transported document is not detected.)
(1) Check for any faulty sensors while executing the copying operation and test mode.
(2) Check the connection from operation panel unit to the SCNT board (JOPCNT1).
(3) Check the connection from operation panel unit (J4, J5) to the any sensors.
(4) Replace the faulty sensor (Document sensor ass'y or Document edge sensor ass'y).
(5) Replace operation panel unit.
(6) Replace the SCNT board.
Chapter 3: Maintenance & Service
3-29