Default Transponder Frequency Changes
If you use 12129 as the Default Transponder Frequency setting to help your Sky digibox boot up, then on the 31st May 2012, this frequency was not carrying any channels, and no longer helped in booting a Sky box up.
You can use an alternate Frequency code of
12207 v 27.5 2/3 – the Sky News frequency
12051 v 27.5 2/3 – Turner Channels
11895 V 27.5 2/3 – MTV group of channels
12285 V 27.5 2/3 – Sky Living
In fact you can use any frequency that you know you can actually receive.