Solved Wifi Huge Problem Tried Everything Macbook Pro 13 Retina Display Late 2013
Chosen Solution No wifi option change 3 wifi card and rio board flex change OS X and tried pram smc reset not working, check the voltage in j9510 Pin4/2- no beep or value Pin 4- pcie_ap_r2d_n Pin2- pcie_ap_r2d_p Solved A common issue with this model when you have WiFi issues is a bad Right I/O Board Flex Cable Apple P/N 923-0559. As you already swapped out the AirPort board (the correct one I hope) Thats what I would try next....