Canon i-SENSYS MF744Cdw

For checking ghost due to transfer failure (TYPE=13)

Check item	Checking method	Assumed cause
Ghost	Check the degree of ghosting (area where the density is too high or low) in halftone areas.	Cartridge error ITB Unit error

For checking the density patch (TYPE=14)

Check item	Checking method	Assumed cause
Density	Check the density of each patch after calibration.	Cartridge error ITB Unit error Secondary Transfer Roller error Soiling on the Color Displacement/Density Sensor Reader error
Uneven density	Check the difference in density among patches.	Cartridge error ITB Unit error

For checking transfer (TYPE=15)

Check item	Checking method	Assumed cause
Uneven density	Check that there is no uneven density in the solid area of each color.	Laser Scanner Unit error Cartridge error Primary Transfer Pad error
Black line (colored line)	Check that there is no black line (colored line) in the solid area of each color.	Scratches on the Photosensitive Drum Soiling on the Primary Charging Roller
White line	Check that there is no white line in the solid area of each color.	ITB Unit error Secondary Transfer Roller error Soiling on the laser light path

For checking developing performance (white spots) (TYPE=21)

Check item	Checking method	Assumed cause
Gradation	Check the gradation performance.	Cartridge error Soiling on the Color Displacement/Density Sensor ITB Unit error Reader error
White spots	White spots near the solid patches in halftone patches just before and after the solid patches	Cartridge error

For checking resolution (TYPE=22)

Check item	Checking method	Assumed cause
Line	Check the position and interval.	Laser Scanner Unit error Main Controller PCB error

For checking banding image (TYPE=23)

Check item	Checking method	Assumed cause
Line	Check the position and interval.	Cartridge error Main Drive Unit error ITB Unit error Fixing Assembly error Error in the feed path Paper slip at paper pickup

4 colors (landscape) (TYPE=24)

Check item	Checking method	Assumed cause
Line	Check the position of the line, and check whether the line occurs in all colors.	If it occurs during copying but not with this PG: • Reader error If it occurs only in a single color: • Cartridge error • Laser Scanner Unit error • ITB Unit error If it occurs in all colors: • ITB Unit error • Secondary Transfer Roller error • Fixing Assembly error

4 colors (portrait) (TYPE=25)

Check item	Checking method	Assumed cause
Line	Check the position of the line, and check whether the line occurs in all colors.	If it occurs during copying but not with this PG: • Reader error If it occurs only in a single color: • Cartridge error • Laser Scanner Unit error • ITB Unit error If it occurs in all colors: • ITB Unit error • Secondary Transfer Roller error • Fixing Assembly error