If the headset detects a problem while charging due to following causes, the indicator (red) may turn off, although charging is not complete. In this case, charge again within the charging temperature range. If the problem persists, consult your nearest Sony dealer. Turn off the headphones or speaker, and then wait a moment while pressing and holding the power button.

The pairing procedure might be different for a device which has just been unboxed and a device which has already been paired before. Do not get the headset wet. If you touch the headset with wet hands, or put the headset in a damp article of clothing, the headset may get wet and this may cause a malfunction of the headset. In [Settings]→ [Devices]→ [Bluetooth & other devices], make sure that the caption below [WH-1000XM4]says‘ Connected voice, music’. If this is the case, the headphones have been paired and connected successfully.NOTE: The procedure to set to the pairing mode differs according to your device. For details, refer to the manual supplied with the product. NOTE: If the device name is not displayed in the Bluetooth items, there is a possibility that the Bluetooth function is set to off. Set the Bluetooth function to on. If you have previously connected the headset to this BLUETOOTH device, only an HFP/HSP BLUETOOTH connection may be made when the headset is turned on. If this happens, use the BLUETOOTH device and make an A2DP BLUETOOTH connection.

Due to the characteristic of BLUETOOTH wireless technology, the sound played on this unit is slightly delayed from the sound played on the BLUETOOTH device during talking on the telephone or listening to the music. Noise or sound skips may occur depending on the BLUETOOTH device connected with this unit, the communication environment or the usage environment. The above procedure is an example. For details, refer to the operating instructions supplied with your iPhone. NOTE:The second option will reduce your sound quality compared to the first option because it favours signal strength over sound quality. NOTE: For how to enter the pairing mode onyour Bluetooth device, refer to the manual supplied with your product.If there is still no audio, try pairing the headset or speakerto another computer or to a cellular phone that has Bluetooth audio streaming capabilities and supports the Advanced Audio Distribution Profile (A2DP). Set the Bluetooth settings on your Android device to ON and delete the device information of the headphones or speaker. By holding an NFC-compatible device near to the N-Mark on the headphones, the headphones and mobile device pair and connect via Bluetooth. If the pairing information was deleted by initializing the headset, etc., delete from your iPhone the pairing information for the headset, and then pair them again. Once the computer detects the device, it will then automatically proceed to installing the driver, after which the device will be added to the computer's list of devices.