[Problem with motor or sensor]

Hello,

Today I received and tested the ultimaker 2.

Firstly I got the leaning/shifting issue as discrebed here : http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#leaning

So I removed the cover on the left and tightened the screws (all of them were already tightened by the way)

Then I put everything on place (encountered some difficulties the first time).

Now I have a second big problem, the print head can no longer go to the Y home position, when he attempt to go to the initial position it just tries to force the way and makes a very unpleasant sound.

I noticed the stop sensor was at the wrong side, then I put it on the good side but I still have this issue.

I here the"click" sound of the sensor though.

I removed the cover and checked if the wires of the sensor were not damaged, checked if it was plugged correctly to the board.

I do not know what to do, can you help me ?!

Thank you!