Hey guys, it's been a little while since I've been here. I've slowly built up a decent little sound system. I just added to my collection an Onkyo auto-return turntable from my dad. Problem is this piece that isn't connected obviously stops me from being able to properly lower and raise the arm. I can't figure out if i'm missing a piece, or if that white plastic tube isn't supposed to be there. Anyone know how this piece goes back in?

btw, if anyone knows about Presonus Fireboxes, let me know... I'm having trouble setting it as my default sound card.