This model is not supported by Dell for Win 10 (no Win 10 drivers).  You are probably limited to the generic Windows installed High Definition Audio driver.  Some Dell's required Dell drivers for audio I/O to work properly and have jack detection.  The High Definition Audio Driver does not have this. One thing to try, Dell does list a Windows 8.1 audio driver.  Give it a try in default Win 10 and if that does not work, try installing it in Compatibility mode for 8.1.   [URL] If this does not work, your best option for sound is to use a Winn 10 compatible USB connected sound device that has a headphone port.  These are relatively inexpensive.  Under  $25 US.  
Hello, I have a Dell Alienware m17x r-4 I believe. I recently upgraded from windows 7 to windows 10. This is where the problem started. I have a Razer Kraken Pro V2 3.5mm analog headset. On windows 7, the headset worked great, no issues there. After upgrading however, my line-in won't detect any audio. In my volume mixer it shows (which I believe to be the computer's default microphone) the green bars are all the way up. When I select "listen to this device" it plays a single 'pop' then silence. When I select the line-in as my default device and then listen to it, it does not seem to pick up any audio. I have tried countless things and have no idea what the issue is.  Any feedback is greatly appreciated. Thank you!
Line-In not detecting any feedback.