Clipper hood jams at half open - bah! HELP!!!

   

just as the sun appears the hood on the Clipper has decided it wont
open more than halfway.
gets to the point where its standing up like a sail and just will NOT go any further and am not forcing it.
all ideas,tips,hints etc appreciated,i really cannot afford to take it to a garage over this.
it must be something dumb/trvial/easy to fix?!?!
i'm just too thickto work it out.
please help!

nb this is NOT an electric hood just a manual one

cheers

L H