I hope someone can help me. I stopped getting audio output through the mDP cable (to my monitor's speakers) several months ago. I thought it could be the cable. But I have the yellow triangle with ! over the HD audio controller in Device manager. I've disabled it and I've uninstalled it and tried to update driver (Windows says I have the best driver installed) and Roll Back Driver is greyed out. Audio output through mDP-to-HDMI adapter doesn't work as well and changing mDP cable doesn't help either. This started in Win8 before Win10TP came out. I installed Win10TP on a clean partition, and I have the same problem there.