Lost signal

Does anyone have a clue why i get a lost signal after installing aTV flash?

i would let it sit then black screen. One time, it rebooted and got stuck on the apple logo.

Jailbreaked with seasonpass 4.3 firmware

That an be a symptom of ATV2 having a network problem. It can be a good idea to initially use a wired network if at all possible, and if you want WiFi configure that when you are already up and running.