Halo 3 skull HELP!!!?

[david h]

Ok i go to the room in the Covenant with the prophet.I kill him and all the flood then I jump through the rings in the order4 6 5 4 5 3 4 and i DONT touch the rings but the skull dosnt appear please HELP ME GET THE SKULL!!!!!!!!!!!
Oh andi have the game on HEROIC!!!HELP!!!!!!!!!!!!!!

 

[oldschooler92]

you have to start at the begining of the level, not at any of the checkpoints. other than that I have no idea.