Power light does not light up when my Philips headphones are connected to power

The red light, indicated “POWER”, is only activated as soon as: you have connected the DC power supply to the base unit/transmitter * and you have connected it to an audio source * and you have set the sound volume level of the music source to a reasonable fixed high level After a few seconds your wireless headphone transmitter base unit will automatically switch on. Note: if the music sound level at the input is at a constant low volume (or off) for some time, the transmitter will automatically switch off.