Faulty electronic sunroof in '96 850 Turbo Wagon

[Adrian]

The electronic sunroof in my '96 850 Turbo wagon won't close. When I press the dash switch, it moves to the half-closed position and then returns to the fully open position. The fuse is ok and I can't see any obstruction in the window tracks. Does anyone out there have any ideas as to what may be going on.?