headphones - do not seem to operate when plugged in headphones jack

When I plug my Sennheiser PX 100 headphones into either jack of my Dell XPS 15 L521X notebook PC, I do not hear any sound emanating from the headphones, and sound continues through the notebook PC speakers. I keep my PC Windows 7 up to date and I have confirmed the headphones operate normally when used with an iPod. Perhaps I am being overly presumptious--I thought that plugging the headphones in the headphones jack of a notebook PC should automatically mute the speakers and route the sound to the headphones. Any suggestions for troubleshooting this situation?

Thanks for reading and any suggestions.

PG

 

If the headphone jack isn't damaged, I would have to guess that the audio drivers for your laptop from Dell's support website might not have been installed.

Link: http://www.dell.com/support/home/us/en/19/product-support/product/xps-15-l521x/drivers

 

Thanks for the suggestion and link. When I downloaded and installed the latest audio drivers using the link, I received a message that the previous audio drivers were about to be uninstalled, suggesting my PC already had audio drivers installed. Nevertheless I proceeded to install the latest audio drivers and afterwards the headphones operated normally with my PC. I'm not sure why simply updating the audio drivers would correct the problem, but regardless I'm glad the situation is resolved.

Thanks again,
PG

 

I have an XPS 17 and had the same issue. The reason why installing correct driver helps is that jacks are programmable by the audio driver. Until the driver sends information to the jack about what it is supposed to be (headphones, part of 5.1 etc) it doesn't pass sound through.

 

Thanks for your insight.

PG