Check that the speaker’s AC power cord is firmly attached to the speaker’s AC In jack and plugged into a working AC outlet.
If your AirPlay or Play-Fi compatible wireless audio device is in standby and you are attempting to start a new audio stream, the device should come out of standby automatically. If, after selecting it in the AirPlay or Play-Fi menu, it remains in standby, select another wireless speaker form the selection menu and then attempt choosing your wireless audio device a second time.