The unit is HTS3357 .The

Question

The unit is HTS3357 .The remote control cannot switch the unit on,only off.This is a brand new device and otherwise works well . It can be switched on by pressing one or another of the controls ,i.e. tv ,radio etc. but the on/off switch is inoperative except to switch off. In spite of the newness of the unit I have put fresh batteries in the remote and also tried removing all external connections (except for mains) and the old trick of unplugging the mains for half an hour or so all of which attempts have proved unsuccessful