3ds hinge keeps popping back

Dear people from the internet,

My brother dropped his 3ds XL and hereby he broke the case of his 3ds XL. My other brother and I bought him a new case and I'm trying to put the motherboard from the old case in the new one. Since the hinge got lost, I bought a new one for him, but I can't seem to put it in the case. I tried to follow the steps from this movie (https://www.youtube.com/watch?v=dVn_m_OI... see 10:24 ) . I did al the other steps via ifixit pictures, but I couldn't find a good picture for the hinge.

Whenever I try to open the 3ds XL, the hinge keeps popping back (see https://vimeo.com/200072013).

Does someone know if I'm doing something wrong or if I bought the hinge for another 3ds or something?

Thanks in advance by a sister who lost all hope...