The speaker does not turn on, or the speaker automatically turns off.

Check the following:

• Depending on the specifications of the USB AC adaptor, when you use the speaker with high volume, the remaining battery may decrease or the speaker may turn off even though the adaptor is connected to the AC outlet (mains). This is not a malfunction. If this occurs, turn off the speaker, wait until the speaker is fully charged, and then start using it again.
• For environmental considerations, the speaker system will automatically enter standby mode twenty minutes after the playback stops. To avoid this, use the Sony | Home Entertainment Connect or Sony | BRAVIA Connect app to turn off the Auto Standby setting.