I Have A Vizio LCD Flat Screen TV That Shuts Itself Off. Sometimes It Shuts Off At Short Intervals, Sometimes It Runs For Hours Without Shutting Off. Do You Have Any Suggestions?

It's not the sleep timer and its not a safety measure either.  I have a vizio tv that is doing the same thing, I got it from costco about 6 months ago.  I have comcast cable and they said they have been seeing a lot to tvs with this issue, and they say its a week signal from the cable company and that some of the tv models have firmware that can be upgraded to fix it or not make it happen so much.  They will be updating my firmware tomorrow (vizio).  I actually want them to replace it with something else because this is just not right.

Some tvs have a sleep timer on it and if it is accidently programmed the tv will turn off at a certain time.  You may want to look at the users manual for more info.  Or call a local place that fixs tv's for some more input before paying someone or getting a new tv.  I had a tv once and it did the same think.  I had to get into the menu with the remote and figure it out it had something to do with a set sleep timer so the tv would shut off at a certain time if the timer was set.  It sucks if you don't have a remote though hopefully you do.  Good luck.  The answer above is a good answer too, she is probably right, but you can look into mine too, just a suggetstion.  Good luck once again.

It could be a faulty sleep timer. I would ask the manufacturer