@souravmajumder time to open it up and to check the power supply. use this guide [guide|108009|BOSE SoundTouch 30 Power Supply Replacement - iFixit Repair Guide|new_window=true] to get to it. Check all the ribbon cables as well as the power supply itself. Look for anything abnormal, like burned, charred or even missing components, check the fuses for continuity. You will also need a multimeter to check for power on that board. Take some well-focused pictures of your power supply, then attach those to your Question. That way we can see what you see. [guide|21499|Adding images to an existing question - iFixit Repair Guide|new_window=true] and hopefully guide you further.