how to fix a lanzer 7" touchscreen dvd player for a car?

i bought a lanzer 7" touchscreen item # sdbt75nu off of the street and im having some problems with it first off the speaker wire outputs dont work (how can i fix them) also the screen seems stuck in the open position(with the screen out)
does anyone know how i can fix this or to whom i should talk to so i can alleviate this problem? feel free to contact me at yahoo username johnboi614