Canon PIXMA MX340 Simplified Service Manual page 29

(8) Sensors
DES / DS Sensor
LF Encoder Sensor
Sensor
DES / DS sensor Detects paper feeding and ejection from the
ADF.
ASF / PE sensor Detects paper feeding and ejection from the
rear tray.
Cover open sensor Detects opening and closing of the document
cover.
LF encoder sensor Detects the number of times the LF encoder
rotates, and controls its drive.
Carriage encoder Detects the position of the timing slit film, and
sensor controls printing.
Carriage Encoder Sensor
Function
(28/37)
ASF / PE Sensor
Cover Open Sensor
Possible problem
- No paper in the ADF
- Paper jam in the ADF
- No paper in the rear tray
- Paper jam in the rear tray
- The carriage does not move to the
center.
- Uneven printing
- Uneven printing (due to grease
attached to the timing slit film)
- Carriage error