Answer to "My sound just stoped"hi, What is your laptop model? OS?
Answer to "How to remove bios password?"hi, Remove the battery and press the power button for more than 10 seconds, it will reset the bios settings to factory default. All the best.
Answer to "Can't hear music playing without headphones"Hi, there can be multiple reasons for this issue, if the headphone socket was given a rough mechanical stress [Usage of incompatible headphones]. or it might be a software issue [In that case you can try a Factory Reset]. But without a proper diagnosis its hard to figure out.. All the best..