Sound cuts out

We originally bought the previous version of this TV last Nov. and returned it several months later when the sound started cutting out. It would just go out at random times and the only way to bring it back was to turn the set off wait a minute and then turn it back on again.

We returned it because of this problem and we were given the newer model of the same set. The exact same thing is happening.

Is there a problem with the set or with the wiring at my house? Before we had the Philips we had a smaller set and there was no problem with the sound. I have done an Internet search and I do see other talking about this problem.

Ideas?