Hi, i have a Notebook Sony Vaio PCG-K33 it comes with a Realtek AC97. My pc is 2 years old and never had any problem with it, but last week i was listening music on my headphones and when i unplugged them the sound didn't come to the mainSpeaker, wich is really rare... I tried to reinstall the drivers, deleted and reinstales on system manager and nothing seems to work. I checked the setup on the Sound Device manager and everything looks fine. Is anyone outthere with this problem or anyone knows how can i fix it? Thanks in advance for any help you can provide.

This is probably not a software problem, but a hardware one. Normally inserting the headphone plug switches off the speakers and removing it turns them back on. If the jack is 'loose' or wobbles with the plug inserted then the jack may be damaged or the solder joints broken. This is especially so if the headphone cord was yanked or jerked.

the 'switching' is normally a purely mechanical operation where the insertion of the plug actually pushes the metal contacts apart, disconnecting the signal to the speakers. when the plug is withdrawn, the contacts should spring back together.