Panasonic Home theater SA-HT930 unit not responding to remote?

I got a Panasonic Home theater SA-HT930 which the unit does not respond to the remote. I don't know what my son did to it. It turns ON on the remote but thats it after that its does nothing else not even turn OFF. the remote works fine I use it on TV which is Panasonic too. I tried using the TV remote and its does nothing.
Any one nows if there is a Lock or something that might be ON by mistake??
Thanks