My Lenovo Laptop T500 had no problems until this week. Somehow the audio driver got replaced by a Conexant HD Audio Driver. After the reboot I noticed that the internal speakers stopped working and only gave a little crackling sound.
As it worked minutes before I was quite sure it was the driver. I removed it, updated it, played with it, but it would not recover. And Lenovo insisted on reinstalling the latest version.
A lot of people said it was hardware related or a loose wire or so. I just did not believe this. Then I found some people who had been playing with the ‘Night Switch’ which seem to fix it for them. Unfortunately not for me.
I noticed, however, that I could not select the speaker output in the crazy setup screen from Conexant. It was just headphones and SP/DIF.
Then I noticed something else: on the Audio Director page I could choose between Classic and Multi-stream. And voila, the blue testbutton played audio through the speakers, the red played through the jack and headphones.
So Multistream it is.
Now I could choose speakers as well on the homescreen (Volume Mixer). It seems this did the trick.
The setup is wrong, the problem rediculous but I hope it helps someone else to solve this, until a fix is presented. It is still buggy, does not detect a headset is plugged in anymore, but at least I can choose to have speakers again with a work around.