This is the bottom of the logic board. Not much to see here--something large covered by another heat sink. At the top right is a plastic cover over the LED. Four ethernet ports, one USB port, a power jack, and a reset button. The Apple part number on the airport card is 603-9396-A.

Here's a <a href="/Guide/200/images_large/airport_logic_bottom.jpg">hi-res</a> photo of the bottom of the logic board.