Tomb Raider: Legend Help please!!!

[Xanime_angelX]

Hello! I have been experiencing a problem in Tomb Raider:Legend for a while and i really need help!:
i am presentally in the Japan level, and in the room with the offices and the big screen tv. It says you need precision shooting to shoot the locks on the top of the tv to shoot it down. But sadly... the precision shooting does not work, or i might just be pressing the wrong buttons.
So please fellow gamers, i really nees you advice, as i cannot proceed further into the game. Just tell me what buttons i need to press or whatever. Please help! ^_~