The speaker is turned on, but no sound, how to fix it?

The speaker is turned on, but no sound, how to fix it?

The speaker itself can turned on, connect to bluetooth device, and lights indicator (white and blue) are on, but it cannot generate any sound (bluetooth or 3,5 aux cable). I tried to unmute it (holding both volume button), maxed out the volume but nothing happened. What should i do to fix this?

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