Please try the following to resolve this issue:
Make sure your speaker is connected to a working AC (mains) outlet
Make sure you are using the Bose power supply that shipped with your speaker, or a Bose accessory charger
If you are using a surge protector, try plugging directly into a working wall outlet
If the above steps are not successful, you can also try temporarily putting the speaker into “Ship mode” which will reboot the internal processer. To put the speaker into Ship mode, follow these steps:
Connect the speaker to power
Press and hold the Multi-function button for 10 seconds
While continuing to hold the Multi-function button, unplug the speaker from power
Release the Multi-function button
The product is now in Ship mode. This is essentially a fully "off" state and it will have no power or functionality. To take the product out of Ship mode and wake it up, just connect it to power. We recommend you allow it to charge for at least 1 hour.
Note: Putting the system into Ship mode reboots the processor, but does not erase any settings, like language selection or paired Bluetooth devices.