Sony MDRRF985RK Wireless RF Headphone, Black

Wireless 900MHz FM wireless headphones, 40mm driver , Easy-adjust headband , Noise reduction system for minimal transmission noise, Automatic tuning for optimum signal reception; The green POWER LED of the transmitter will NOT light when the headphones are seated on the transmitter.It will remain lit only while an active audio source is providing audio.If your headphones are seated in the cradle of the transmitter and fully charged, neither the POWER light of the transmitter nor the CHG light of the headphones will be lit. If you unplug the transmitter and plug it back in, the green light will flash for a moment.The green POWER LED of the headphones will light up whenever the headphones power switch is turned from OFF to ON, and has enough of a charge to function. The green LED flashes, dims, or remains off if the headphones need charging.Sometimes noise can be heard from the cable brushing against clothes. This noise may be reduced by using a clip to keep the cable in place.Verify the power adapter for the transmitter is plugged into a working AC outlet.Make sure the other end of the AC power adapter is connected to the DC IN jack on the transmitter.Place the headphones on the transmitter so that the charging pins on the transmitter make contact with the connectors on the headphones.A charging time of 3.5 hours is required for an MDRRF985RK.If there is no charge indicator, try plugging the transmitter into a different AC outlet, just to make sure there is not a problem with the first outlet.