I plugged my original Nexus 7 into my Mac earlier today to build an application onto it for testing. It failed, and then I realized that the tablet did not appear to actually be connected to the computer.
Symptoms: Tablet charges, but no notification about being connected. Tablet does not appear in
./adb devices (nor in
./fastboot devices when device is in bootloader), and Android File Transfer will not find it.
Tried: Rebooted both tablet and computer, tried different USB cables and USB ports. Tried MTP, PTP, and neither. Tried USB Debugging on and off.
My Nexus 4 connects to the computer just fine. Both N4 and N7 are running Android 4.4.2
UPDATE: Tested my roommate's Nexus 7 (same model) on my computer, and it connected fine. Tested my Nexus 7 on his computer and saw the same lack of connection
EDIT: now fairly convinced that it's a faulty hardware USB port on the tablet. Wiggling the cable will cause the device to show "USB Debugging Enabled" and "Connected as Media Device" notifications, though the computer still doesn't recognize it