We are lucky and get a free Apple TV Dev Kit. Unbox and plug it into TV, then find a black screen on 4k TV. we first thought it could be a 4k TV compatibility issue. after trying an old, and googling again.finally get to know the dev kit comes with nothing in the hardware, no tvOS in it at all. Just download and install tvOS beta. Share the findings here to save others’ time. The following is from the apple forum:
Here are some tips on setting up the new Apple TV Dev Kit, because you can’t just plug it into your TV as soon as you unbox it.
First you need to download the tvOS Beta from here: https://developer.apple.com/tvos/download
Next you need to install the beta to the Apple TV, it doesn’t come with it installed already.
1. Plug the Apple TV into an outlet and into your computer with the usb-c cable
2. Launch iTunes (v12.2.2 works fine)
3. Option click (hold on the option key when clicking, or get the no available software error message) the “Restore Apple TV” button and select the tvOS Beta .ipsw file you downloaded before.
Then you need to register your Apple TV with your developer account.
1. In Xcode (v6.4 or higher) under “Window > Devices” click on the Apple TV
2. If it’s just showing the device logs at first click the down arrow to see the device info
3. Copy the Identifier and register on the dev center just like you would an iPhone
That’s it! Just plug your Apple TV into your TV and set it up. If you have iOS 9.1 installed on a device you can use that to set it up easier, otherwise you can just use the remote.
Good luck building your tvOS apps, I can’t wait to see what you create!
see this for details and some Q&A: