While viewing, my tv reverts to standby mode by itself, please advise what the problem may be?

There is a well known solution to this type of problem and it works every time. It is backed up by a well known phrase or saying and it goes something like this. If all else fails, read the instruction book. If that doesn't work you could have something very rare these days, a faulty television set. I am assuming that you put batteries in the remote control? Of course you did.