iPhone 4 Home Button
It is under the Roof, the black cover in the middle of the fan. The card handles Airport and Bluetooth. There are four antennas connected to the card.
Dominic is correct. The Airport/Bluetooth card and the antennas are housed in the fan area. It is under what is being called the Roof (the black cover in the middle of the fan). It is just adhered by glue, use a couple black sticks to pry it off.
Tom, it is only four antennas. My guess is three for Wi-Fi and one for Bluetooth.
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