Epson Perfection 1640SU Office scanner with Auto Doc Feeder (ADF). The ADF plugs into the back of the scanner via a DIN-8 plug. (The ADF is model EU-34, pn B813222.)
The scanner will scan documents on the flat bed glass with no problems.
When the ADF is used, the paper feeds through the rollers smoothly. No jams or other feed problems.
The resulting scan in ADF mode is all vertical lines. I tried different resolutions and other settings. Also tried different applications. Same results.
A tech at a local Epson authorized repair facility said that this is a common failure. There is a calibration strip at the "home" position on the bottom side of the flat bed glass. Over time this white strip changes to off-white and when calibration is done at power-on, incorrect calibration results.
The Epson tech says that this is a quite common failure mode and he does many of these repairs on several different models. (I didn't ask if it was common to other than Epson.)
How does this calibration work such that it succeeds for flat bed scans but fails for ADF scans? Can someone explain?
Thanks.