that sounds like you battery to me. Check you
battery, voltage on each cell
receiver take it apart and see if anything looks damaged. Don't lose a single thing though.
and ESC. how hot it is after couple seconds of spin up. anything burnt? etc
Also check everything on your head parts and look carefully on your tail. Even slight crash can bend, break or disconnect something. I crashed my belt-cp on easter and it wasn't hard at all! and i lost a bunch of head parts and then the tail boom was bent. I was surprised because taill boom took quite a bit of force to bend back to its place..