Device Missing From Android Device Manager
As you may know, Android Device Manager works on all devices running Froyo or later, and it installs itself as a Device Administrator. However, some users still experience issues with their device missing from Device Manager. If your Android device does not appear in Android Device Manager, or if you see Unknown location despite your device being online follow these steps: Check if Android Device Manager is enabled: Got to Settings > More > Security > Device administrators and make sure Android Device Manager is enabled....