I tried to replace original AirPort Extreme card with another one that I bought from eBay. Both cards look very same and is BCM94360CD model. The new card’s Wifi works except when there is USB 3.0 drive connected. When I plug a usb 3.0 drive, wifi started dropping and reconnecting. I am using 5g channel so it shouldn’t because of usb and 2.4g signal interference. I tried another BCM94360CD card and see same issue. Wifi and Bluetooth works except when plugging usb 3.0 drive and then wifi starts to reconnecting. I tried BCM943602CDP card and Bluetooth becomes 4.2 but wifi still has this problem. I tried Catalina install USB and the install program cannot connect to wifi with same problem. Mojave install program has same issue. I tried reset smc and nvram and doesn’t help. Bootrom firmware is 137.0.0.0 the newest. I tried Ubuntu live usb and seems doesn’t have this kind of problem. Seems like Mac OS can only work with original card but Linux can work with other cards. Really strange. Please help if you have some hints.
Last edited: