I'm very sorry for any inconvenience this may have caused you. This sounds like it may 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 have brought below model TV from walmart in Dec 2009
Samsung 40'' Class 60Hz 1080p LCD HDTV, LN40B500.
It was fine till yesterday. Today onwards it started changing channel automatically and changing mod automatically, etc.
It's in a situation could not watch TV.
How do I get it fixed? I stay around Washington DC. Can I get replaced? Is there any tips to fix this?