We purchased one for my parents a few weeks ago - it has worked fine until yesterday - now it doesn't work at all. Message is Scan Channels ---but doing this doesn't change anything -- it says it has no network signal -- I have tried all the various set ups --- no good - it finds 44 digital channels on search but then comes up with scan channels message again. Any suggestions? P.s 2 other TV in the house are still working which is what puzzled me about the no network signal message.

You should call tech support so they can walk you through checking it out. You may have a bad circuit board connection. That's what it sounds like. You may have to return it.