The headphones are unplugged. It seems to be a hardware problem because when i check the mixer, i can see the volume bar moving up and down. I start to wonder if i did not disconnect something when i cleaned the fan .... :-S
Any suggestion anyone?
(Go to safe mode, remove sound device, restart into safe mode (maybe not necessary), install driver, something like this.)
I've searched around a bit, and found some linux threads, where people were struggling with the same problem, and some software magic saved them. That's only to say that it's not 100% sure that it's a hardware problem...