In the big round hole the motor engages with the two threaded cables that move the two sides of the blind (left side and right side)
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Notice that there is a gap between the two plates.
This gap permits the motor to keep turning even when the blind has reached the full closed position. This causes the noise that is heard in the video that ezdanny has posted (youtube.com/watch?v=XLl7k3fRVlM )
View attachment 103208
Skywindow fixed!!!!!!!
Many thanks to velissariouc, who gave me the key to solve the problem!!! I´ve found a skywindow in a local junkyard, changed the part in the picture and ready to enjoy again of my great roof!!!
Thanks again man!!!!