XPS 15 9500, external microphone doesn't work

Hello,

I've been stucked in problem with the external microphone on my XPS 9500.

I have to record audio, but the external mic doesn't work. 

I plugged the mic in, a maxx audio pop-up appeared, I chose Headset. In the Recording tab, Jack Mic was actived, I ticked Listen to device, but when I try to say something, the wave volume in the right didn't do anything and I didn't hear what I said.

I disabled Jack Mic and set Defaut Device for Microphone (section 2), only microphone on laptop worked, the external mic didn't work.

I tried plug the external mic in another laptop (Vostro 3450), also chose Headset in Maxxaudio pop-up, there was no Jack Mic, only Microphone there but it worked well. Microphone in Recording tab on Vostro 3450 recognize external mic automatically and when unplugging the mic jack, it automatically switched to the laptop's microphone.

XPS 9500 and Vostro 3450 both have only one 3.5mm port, but why the Vostro 3450 works so well and the XPS 9500 can't? Where did the problem come from with a very expensive laptop?