Why won't its adf feed originals?

The Automatic Document Feeder no longer works when I try to use the it to process either a single or multi-page original.

When I place a piece of paper in the ADF tray and advance it into the opening, I hear a "ding" sound.

The text "Original Loaded" appears on the touchscreen.

But then when I try to start to scan or copy or fax, the printer makes a screeching noise.

Its touchscreen display reads "Reload document, and then restart job."

On the computer screen, a popup (with an "OK" button) reads "A scanner Automatic Document Feeder (ADF) misfeed occurred. Reload the pages into the ADF and try again."

If I press "OK" and try again, I get the same results.

Although the ADF worked properly for several years, this happens now every time I try to use the ADF.

I would like to get this ADF working again.

Are repair/replacement parts for the ADF rollers/feed mechanism available?