I was reading every post I could then I found the one below and it worked for me. Here is some other info that may help. The light will start flashing slow when the USB is connected. As you hold the menu and play/pause buttons the flashing will increase. I held those two together waiting for notification that it was in DFU mode but it never came until I let go of the buttons. Hold them for 7 seconds then release and it will take a few more seconds for the box to let you know that the ATV has been recognized
Connect ATV2 up to a power source (contrary to the instructions)).
Hook up the micro USB.
Then remove the power cable (standby light should be blinking), wait a second or two and then press ‘menu’ and ‘pause’ together for 7 seconds.