From 1.6Mm To 1.7Mm Pitch Uneven Density Occurring When Coated Sheets Whose Basis Weight Is 200Gsm Or More Are Continuously Output - Canon imagePRESS C850 Series Troubleshooting Manual

From 1.6mm to 1.7mm pitch uneven density occurring when
coated sheets whose basis weight is 200gsm or more are
continuously output
[Symptom]
From 1.6mm to 1.7mm pitch uneven density [a] may appear in main scanning direction on the second sheet or later when coated
sheets whose basis weight is 200gsm or more are continuously output. The symptom is prominently seen on a black halftone
image. The arrow [b] indicates the direction of feeding.
[Cause]
Because the paper feeding speed of fixing assembly is faster than the speed of secondary transfer unit, the media will be pulled
between the secondary transfer unit and the fixing assembly. Therefore, the vibration of fixing idler gear is transferred to the
scanner and that results in the above symptom.
[Service work]
When the above symptom occurs, adjust the fixing speed to minus side for every sheet in the management setting for media type
in user mode.
1) Have the customer log in from System Management Mode in user mode.
2) Go to Select Settings/Registration > Preferences > Paper Settings > Paper Type Management Settings, select an appropriate
paper type from among the list, press "Duplicate" button and then "OK" button.
3) Enter any name as the duplicated paper type and press "OK" button.
4) Select the paper type copied in the step 3) and then press "Details/Edit" button.
5) Select "Adjust Fixing Speed" and then press "Change" button.
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