I recieved my Apple TV Dev kit today. When I plug the Apple TV into power, HDMI, and USB to my computer, the light on the front just starts blinking fast (after 5 seconds) and a recovery-ish screen shows on my TV. The Apple TV isn't showing in iTunes, Xcode, or the USB tab of system profiler. If there is no USB cable attached during boot, it just starts blinking fast right away (no delay). I'm not sure where to go from here. I have iTunes 12.3.0.44 installed.
I got it to work. I just kept inserting and removing the connector while flipping it until iTunes FINALLY popped up and told me it detected an Apple TV. It took me 7 hours but it's finally setup 🙂 I'm afraid I have a bad connector because it seems like it is really loose but I'll follow up about that later. Right now the Apple TV is balanced on my knee as it's restoring and I'm trying not to move at all 🙂