Only mono sound when plugging in headphone

[mke21]

I suddenly lost stereo sound when plugging in my headphones in the jack-output. No idea why. I’m using pulse audio. I have dual boot with windows, and in windows everything is fine, so this is no hardware issue or something wrong with the headphones. It must be something with the settings. I had a look in pavucontrol, but output seems to be set on stereo output.

This is on a HP laptop. The soundcard is HDA-Intel. On alsa mixer it seems to recognise that it’s stereo, but there is no output on one of the chanels.

Does anyone have an idea where to look to fix this?

[mke21]

I answer my own question:
in pavucontrol, there is a tab “Output devices”. There you can set the volume per channel. Somehow, the “Left Front” was set to 0, setting that higher, makes stereo sound coming back. I have no idea why that became 0.