I've had no sound on my laptop speakers for a few weeks now. The only solution I found was going to AlsaMixer in the command line and unmuting the "Headphone" bar, then the speakers start to work, whereas modifying the volume for the "Speaker" bar does not do anything. When I plug the headphones, the "Headphone" bar correctly controls the sound through the headphones.
I already search a lot on the internet and followed the troubleshooting steps several times with no success.
Does someone has any idea about this? It might come from my dual boot with windows 10 (fastboot disabled)
System: Ubuntu 16.04 (had the same problem with 15.10) dual boot with windows 10 Laptop: Dell inspiron 7520