If it doesn't work or doesn't work the first time, you can try charging it for 2 hours and then try again, because it may be a long time without use and the battery is dead. If it still doesn't work, please check to see if the operating mode is selected correctly, receive mode and transmit mode. 1. Transmitter + Receiver - ① Transmitter mode: transmit audio from non-Bluetooth audio sources (TV, PC, TV Box, CD / DVD player, projector, etc.) to Bluetooth headphones / speakers. ② Receiver mode: transmit audio from Bluetooth audio sources (smart phone, tablet, Bluetooth TV/PC, game machine, amplifier, etc.) to non-Bluetooth headphones / speakers / car / home stereo system. 2. Optical + 3. 5mm - You get maximum flexibility with support for both digital optical jack and 3. 5mm audio jack(AUX and RCA), both audio input and output are supported. 3. Low Delay - Built-in DSP, the Bluetooth audio adapter can reduce Bluetooth delay to provide CD-level high-fidelity stereo sound quality when you listen to music. Stream and control your music with a reliable connection range of up to 33ft(10m). *Operating range can be affected by multiple factors. 4. Dual Link Music Streaming - Connect 2 Bluetooth headsets/speakers simultaneously to your TV to share the movie in transmitter mode, or pair 2 devices to your home stereo system to stream music in receiver mode at the same time. Automatically connect to your previously paired devices at power-up. 5. USB Rechargeable - The built-in 1200mAh battery can provide up to 8 hours of playback time in transmitter mode and 7 hours in receiver mode after about 2 hours charging. Support using while charging. With power indicator light, you can know the working status at any time, which is convenient for you 5.0 wireless audio adapter bluetooth