I have tried to jailbreak my AppleTV 2g with both GreenPois0n RC6 and PwnageTool 4.2.1 for several times, none of them working well. Fortunately one day I incidentally made it work. Here how I did:
- I follow the instruction from http://www.redmondpie.com/how-to-jailbreak-apple-tv-2g-on-ios-4.2.1-untethered-with-greenpois0n-rc6-guide/
- The problem is I can’t go to DFU mode with the instruction given. It always fails at the end.
- To FIX this problem, I just enter the DFU mode before running GreenPois0n
- First I plug in both USB cable and Power cable in to AppleTV then press Menu + Down until the white flash blinking rapidly.
- Next release both button, the white light will stop blinking.
- Now immediately hold Menu+Play until the light
- Once in DFU mode (iTunes will show up), run GreenPoisi0n. It will start jailbreaking suddenly.
- Wait for 5 minutes, click complete and it’s done.
- PS. my AppleTV was stuck in recovery mode after the jailbreak process. I have to use RecBoot to kick it out of recovery mode.