I was trying different tricks. Even soldered new audio jack connector to the motherboard of my ASUS U36SD notebook. I've spent lots of time, but found the solution! It is not a hardware issue. It is software/driver glitch :)
So if you have the same issue with your notebook: no sound from speakers, but headphones works. Here is the solution:
- Restart computer.
- Open BIOS/Setup console, by pressing F1, F2, F10 or Del key depending on your notebook model.
- Choose "Load Default Settings" option at the beginning.
- Then search for "Ring on Boot" or "Boot Sound Volume" option(s) and TURN IT OFF or set the volume level to ZERO!
- Save BIOS/Setup settings and restart computer again.
Now you can hear sound from the internal speaker of your notebook, laptop or tablet :)
Let me know if this workaround helps you and please specify the model of your notebook in comments. Thank you.
BTW, do you know about my Auto Mute software utility to make computer silent by default? :)