Maybe I will dismount the complete unit to replace this (cheap?) cable up to ADF unit. Could be the problem as my ADF does nothing than saying - no document. Anyone having a tech repair guide for me?

To remount the SSD drive I used a gaffa tape (that stuff musicians are using to fix cables), did cut a piece of some centimeters and folded it, so that a open piece with the glue can be sticked onto harddrive. Gaffa tapes usually are around 4 to 5 cm wide so it is easy to maneuver the SSD with the two screws easily into the holes in front of the case. After things are in place and before remounting antenna I removed that tape from the harddrive.

Maybe this helps others.