The laptop has no sound coming from the internal speakers but headphones connected to the laptop audio jack work fine.
1. Broken audio jack.
2. Bad speakers.
Possible troubleshooting steps and repair solution:
If you can hear sound from the headphones, it means the sound card and audio driver work correctly. Why can you hear sound from the headphones but not from the laptop speakers? Here are the two most common problems:
1. The audio jack has a small switch inside. When you plug the headphones, the plug activates the switch and the sounds switches from the speakers to headphones. It’s possible that the switch inside the audio jack got stuck and because of that, the sound works only when headphones are connected. Try plug and unplug the headphones into the audio jack very quickly a few times, this might release the switch inside the jack and the audio signal will go back from the headphones to the speakers.
Also, the audio jack could be broken, and plugging/unplugging the headphones will not help. In this case, you’ll have to replace the audio jack which is not easy because the jack is soldered directly to the motherboard or soundboard.
2. There is a chance that you have bad speakers but it’s not very likely that both speakers fail at the same time.