When i switch it on it works well for about 5 mins, but then on the main box thing / dvd of the sound system, theres written "rear chk" and the back speakers dont work. Then i switch the system off and on again and it comes again, but the same thing happens again. Also i cant find the menu or settings, because when i press menu on the remote nothing happens. The tv 'on' light beeps to show that the remote is being used to the tv, and i tried different stuff too, but never anything of the device comes up on my tv. Please help?