Uneven Gloss (Rain Drop Mark) In High Density Area - Canon imagePRESS C800 Series Troubleshooting Manual

Chapter 1
[Caution] Changing this setting may decrease the primary transfer voltage and bring poor image (poor transfer with Bk high density original, etc.).
8) Output the image having shown the symptom, and check that the symptom does not occur. If the symptom no longer occurs, the work is completed.
If the symptom does not show an improvement, go back to the step 2) and change the value of Black by one at a time down to "-5".
9) If the symptom still persists, revert the changed value in the step 2) to what it was and replace ITB.
[Note]
Perform the following operations after replacing ITB.
- Go to Service Mode > Mode List > COPIER > Function > INSTALL >, select INT-ITB and press "OK" button.
- From Settings/Registration > Adjustment/Maintenance > Adjust Image Quality >, select Auto Correct Color Mismatch and press "Start" button.
- From Settings/Registration > Adjustment/Maintenance > Adjust Image Quality >, select Auto Adjust Gradation and press "Full Adjust" button to execute full
adjust following to the message emerges on the screen.

1.1.1.3.5 Uneven gloss (Rain drop mark) in high density area

0031-7732
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Symptom
In the leading edge of high density image area, 3-5 mm width uneven gloss (Rain drop mark)[a] may appear in feeding direction with about 10mm in length.[b] is
the feeding direction.
Cause
Water vapor from paper tends to stay more in the area with weak fixing nip pressure than in the area with high pressure.
When the remained water vapor moves around on the paper, it causes uneven fixing leading to the above symptom. Coated paper tends to have poor air flow making
water vapor in the area with weak fixing nip pressure not distribute and stay. This causes the symptom to easily occur.
Service Work
1) Have the customer log in to System Management Mode in user mode.
2) Go to Preferences > Paper Settings > Paper Type Management Settings, select an appropriate paper type from the list. Press "Duplicate" and then "OK".
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