Hasselblad 949 - Manual (Page 29)

Solution 2: Move the drum to its home position. To do this, run
FlexColor and select Maintenance > Feeder to open the
Feeder window. Then set the Drum position drop-down list
to “home”. Try scanning again.
Solution 3: Make sure that the magazine is pressed fully into the drawer
hinge. See also “Loading Slides” on page 18.
Solution 4: Check that light is not shining directly into the scanner. The
Feeder uses an optical system to monitor the position of the
original holder; this system can be confused if outside light is
shining directly into the scanner.
Solution 5: Check the alignment of the Feeder to make sure the slide
original holder is centered. See “Aligning the Feeder” on page
30.