can't restore atv2 and doesn't show up in itunes

i want to remove the jb and update to the latest iOS.

when i reset the atv , the screen just goes black and it does nothing.

when i hit restore, it says - the update was not successful.

when i plug the atv in to itunes, it does not show up. cable might be bad but i do not have another one to try.

atv2 works fine otherwise.