No sound on second TV

About 10 - 12 days ago DSTV did a system upgrade and since then I have not been able to get sound on my extra view TV. I sent several messages to the Facebook page and they just gave me standard \check this"or \""check that\"" - I have not done anything or changed anything AND I have a friend who has an identical problem! Every setting I am told to check is already correct so now they tell me to take my decoder to the a service centre. Which decoder (I have two) and how will checking the one decoder in a service centre help? They need to send a technician to fix the problem - if it was me alone"