Avision AV620C2+ (DF-1015S/DF-1004S) - Manual (Page 104)

8.4 Replacing the ADF roller
After scanning approximately 200,000 pages through the ADF,
the ADF roller may be worn out and you may experience
problems with document feeding. In this case, it is highly
recommended to replace the roller with a new one. Please
follow these steps to replace and install the ADF roller.
1. Open the ADF front cover.
2. Move the ADF roller tab up as indicated.
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