Component Identity required please!

I've currently got a bit of a battered iphone 4 which among other things is missing a small component on the top side of the board, see pic:

Highlighted in green ( if that wasn't clear)

I've lost my iphone 4 schematics somehow and was wondering if anyone has encountered this part before. (LCD isn't working at the moment, although that's most likely due to corrosion on the connector.)

Thanks in advance.