ATV2

Hi I jail break my ATV2 more than 2 years ago and so far everything is working fine with 5.1 version. I tried to reset and use 5.3 as I am running into AirPlay issue. I switch on AiPlay but I never able to see ATV2 in my iPhone or Mac. So I thought of doing another clean install but every time I try to enable the DFU mode I am getting No Device found error. I tried save firmware signature but getting the same error…let meek now anyone have any suggestion…