Here's the complete trouble shooting guide if you want to walk through the whole thing: http://support-us.samsung.com/cyber/popup/iframe/pop_troubleshooting_fr.jsp?idx=48670&modelname=PN50A650T1F&modelcode=&session_id=PtcvmjJlQ9xmkbhhmdLhL1yr2Jp7ynXsxlT3Z9GfxTRyrGYkH1mq%211358249754%21-1721297013%211336761570011
If that doesn't work, you'll need servicing. Here's the thread where you can find information on that setting that up: http://forums.cnet.com/7723-13973_102-542437/service-issues-click-here-for-help/
-- HD Tech
I've just lost sound on my TV there's no sound from my satellite my xbox my blu-ray ive tried all HDMI's connections and even AV and my old VHS but the TV speakers are ok I can still ear the open up song but none of my inputs will give me sound !!!