Canon LASER CLASS 730i Service Manual page 121

LASER CLASS 730i/720i/710 Chapter 4: Maintenance and Service
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 ADF sensor board (J1) and the SCNT board
(J805).
(3) Replace the ADF sensor board.
(4) Replace the SCNT board.
• The scanning image is abnormal. (Evaluation criteria: Check the cpy
image's faults.)
Nothing is printed.
(1) Check the connection between the contact sensor and CS relay board (J4).
(2) Check the connection between the CS relay board (J1) and SCNT board (J4).
(3) Replace the contact sensor unit.
(4) Replace the CS relay board.
(5) Replace the SCNT board.
The image has vertical stripes.
(1) Clean the contact sensor's scanning glass and white sheet.
(2) Check the connection between the CS relay board (J1) and SCNT board (J4).
(3) Replace the contact sensor unit.
(4) Replace the CS relay board.
(5) Replace the SCNT board.
The image has thick vertical stripes.
(1) Clean the contact sensor's scanning glass and white sheet.
(2) Check the connection between the CS relay board (J1) and SCNT board (J4).
(3) Replace the contact sensor unit.
(4) Replace the CS relay board.
(5) Replace the SCNT board.
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