Windows 10 Detects But Refuses To Play Sound On My Headphones R Windows Nvidia HDMI "not plugged in" (greyed out), video, but no audio Here's my setup Nvidia video card>HDMI out to Sony Home Theater System>HDMI out to Samsung HDTV I use this to get 51 LPCM surround sound for video games It worked fine until I did a firmware update on the Sony unit Now, the HDMI audio is greyed out in Windows 7 audio playbackNo need to panic You're certainly not alone Many Windows users report the exact same problem But most importantly, you can quickly and easily fix the situation NVIDIA is one of the leading suppliers of excellent graphics cardsContinue reading "Fixing the "NVIDIA Output Nvidia output not plugged in reddit