Tomb Raider- Legends For X BOX, mission where Laura meets Amanda and Entity thing...what do i do?

OK...ive come to the part where Laura meets Amanda, and Amanda accuses her of only saving herself yadda yabba ***** *****... now i have pressed all the on thingys right , in order to get t hat glowing ball thing ABOVE my electric gun-blaster thingy lol... now when i blast that Entity or whatever with my electric gun between those metal electric poles, it goes away for a bit. Im just wondering what im supposed to do during that time. I use my gun to move those 4 dangling ball thingys, but all they do is rock back and forth, anyone know what do do? it is the misson in Africa, Ghana.