Scanning Problems - Canon FAX-L350 Service Manual

4.3.3 Scanning problems

• Faulty scanning (Evaluation criteria: Test print is good, but the copied image is poor.)
• The document is not fed.
The document feed motor does not run. (Evaluation criteria: Check it visually.)
(1) Check the voltage (+12 V) at both terminals of C501 located on the MCNT board.
(2) Check the connection between the document feed motor and the SCNT board (J406).
(3) Check the document feed motor's resistance. 5.6 ~ 6.8 /1 phase is normal. ( Fig. 3- V)7 )
(4) Replace the document feed motor.
(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 document feed motor is driving all the rollers. (Check for any damaged gears or
foreign matter stuck inside.)
(2) Check whether the document feed lever is set to manual document feed.
(3) See page 3-4 and clean the separation roller and separation guide.
(4) Replace the separation roller and separation guide.
The scanner unit's sensors are defective (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 between the operation panel unit and the SCNT board (J406).
(3) Replace operation panel unit.
(4) Replace the SCNT board.
Figure 3-7 Document Feed Motor Connector
FAX-L350 Chapter 3: Maintenance and Service
To document feed motor
Document feed motor connector
1-2 : 5.6~6.8
3-4 : 5.6~6.8
3-25