X-Fusion, Ridley fight and the Screw Attack?

Ok, so I've gotten most of the way through metroid X-Fusion and I've gotten all the way to lower PYR and to the Ridley boss chamber... but the fight isn't starting. There are screw-attack blocks/crates blocking the Auxilary power room. Did I miss something? I feel like I've combed every sector about as much as I could without it. Am I a fool and I missed something?