Even I am facing a similar problem I purchased a Sony Bravia KLV52EX 32 inches Full HD LED TV on 10th March 2011 from the Sony showroom in Amritsar. Initially I was using the standard Dish TV st top box with which it was doing fine. But, after I switched to a Dish TV HD (High Definition) set top box 2 months back, I started noticing sound problems. The video is alright, but there is no sound. The sound then comes back after switching one channel up or down & sometimes it does not come even with this manoeuvre. This sound problem is very irregular & I have been experiencing it now since the last 2 months. I called up the Dish tv people, & they changed the set top box & even the HDMI cable, but still it was persisting. Then I noticed thrice that sometimes there was no sound even in the DVD player attached to the TV when no sound was present in the TV too. I called up sony customer care explaining to them my problem. Initially they were not convinced & were blaming Dish tv for the sound problem, but when I demonstrated the sound problem in front of them with no sound coming even from the DVD player, they were convinced & took the TV to their customer care shop for a detailed analysis of the problem. Then after 1 week they called me up telling they could find no major fault in the TV as to why the sound stops suddenly & that they have even changed the sound board in the rear as it is within warranty. They suggested to me the reason for the sound problem could be due to incompatibility of the Dish TV software with that of the Sony TV & suggested me to get an Airtel connection.Sometimes, when the sound is absent, I see the message 'Unsupported Audio signal please check your device output" When I suggested to the Sony people for a replacement, they refused citing that LCDs can't be replaced The problem is still persisting & I am now at my wit's end. Kindly give me some helpful advice regarding this chronic problem.