Alas, it was the logic board

내 문제

MacBook Air (2012) with a "Wifi: No Hardware Detected" error. Bluetooth was working, but not Airport. After a dozen attempts to fix with software, I ordered this replacement card.

나의 수리

Unfortunately a new card didn't solve the problem. The problem was with the Logic Board. $280+tax at the Apple Store.

내 조언

The crazy part about a 2012 MacBook Air is that, if the Airport dies, you can use a $10 EDI 802.11 USB dongle to get online, but you can not connect to the Apple App Store without a working Apple Airport card. App Store checks the MAC address of Ethernet and Wifi, and neither a Thunderbolt nor USB ethernet adapter will work.