Hello, I have a Dell XPS 13 with a WD15 dock, the last days the dell audio stopped working but I fixed reinstalling the drivers (http://en.community.dell.com/support-forums/laptop/f/3517/t/19993911

But also my dock WD15 stopped displaying video or audio. The ethernet and the usb works fine but I cant output any video as the scree says no HDMI signal detected. I've tested the HDMI with other computer and the monitor works fine.

I've downloaded and installed the firmware and driver for thunderbolt and the Realtek driver from here: http://www.dell.com/support/home/es/es/esbsdt1/product-support/product/dell-dock-wd15/DRIVERS?rvps=y 

If I go to playback devices i can see the monitor audio (VW246) but the dock audio shows as not connected:

In windows devices manager there isn't any device without controller.