In this series of MBP, as Dan has mentioned there is a main logic board and an I/0 MagSafe board on the upper left.
This card houses functionality for your MagSafe DC in connection, both audio ports, a USB port, PCI card slot, light sensor, mic, and your airport card.
The airport card seats into a housing mounted on this board over the card slot much like the RAM seats into it's housing on the logic board.
To remedy this issue you will need a T6 torx screw driver and a phillips #00.
1- Remove all of the screws around the otter casing of your MBP.
2- Lift the top case (contains keyboard and trackpad) from the bottom case of the MBP
3- Disconnect the had drive from the logic board
4- Disconnect the ribbon located to the bottom right on the I/0 board that is connected to the logic board
5- To the right of the fan at the top, gently disconnect all wired connections to the logic board. * The first at the top pulls out to the side...the others lift up to come out.
6- Using the T6 screw driver, remove the screws holding in the left fan. (Top Left silver screw holding bracket and wire down, bottom left silver, and bottom right that holds the fan to the logic board)
7- There is a bracket to the left center that holds the airport card and the top sensor housing together and down. - remove that screw and the black and blue connectors (make note of which wire connects to which prong)
8- You can now remove the airport card and the top sensor housing.
9- Follow along the wiring to find their connections, gently and evenly disconnecting them. (Use plastic pry tool) Be careful of pulling to much on the wires or squeezing the connectors.
10- If you wish to replace the logic board you will first need to follow instructions on removing the logic board. There is a wire harness that attaches to the under side of the logic board that is rather difficult and dangerous to attempt removing without first lifting the LB.
11- After lifting the Logic Board and removing all of the wires that prevent removal, there are several T6 screws that outline the board. - Remove them.
12- Between the two audio ports there is a hex with a hole where the bracket you removed earlier will screw into. You must unscrew this hex to remove the board
After all screws are removed the board will now lift from the right side.. up, then once you clear the top edge near where the LCD connections are... you can pull the board to the right, removing the ports from their lower case slots.
- If you are just interested in removing and reseating the Airport card, simply disconnecting the black and blue wire, the T6 and bracket that hold it in... clean with a static free electronics cleaning cloth, and replace into it's housing. Reconnect the bracket and wires. (Black on the left blue on the right... white tucks under the mic.
If disconnecting all of the connectors and reconnecting them does not resolve these issues... there is likely and issue with either the I/0 board, the connectors or wires, or the connection at the logic board. (likely not the logic board connection if you can boot)
Final solution without being able to physically diagnose this myself... after replacing everything (or before removing) try to do a NVRAM reset.
Hold Cmmd + Option + P + R at start up. Hold through the first tone, the system will restart, and you will hear a second start up tone. Release all keys when that second tone sounds.
- If the issues remain, perform a SMC reset.
- Shut down the computer.
- Disconnect the MagSafe power adapter from the computer, if it's connected.
- Remove the battery.
- Press and hold the power button for 5 seconds.
- Release the power button.
- Reconnect the battery and MagSafe power adapter.
- Press the power button to turn on the computer.