So got my x51 a couple of days ago, along with my new sony bravia tv.

Straight away i used the nvidia HDMI port to hdmi on my tv and booted up for the first time

Noticed that during the entire process of windows 8 setup the screen flickered in and out of signal while i was going through the process.

Once id finished set up it lost signal entirely.

So i switched to the Intel onboard hdmi port and it worked fine.

But there was no sound. the only thing in devices was "Digital audio device" and not recognizing my tv as an audio output.

So u plugged in my old pc speakers (2.1) to get some sound.

I thought my this point the hdmi issure was driver related but checked and all drivers were up to date.

I then used DVI to vga adapter to connect it to my pc and it worked fine.

I also tried a DVI to HDMI adapter and this also worked perfectly.

However using these options, there is noticeable audio lag when watching videos which is a pain.

Just want the HDMI TO HDMI port to work properly, ive tried 3 different hdmi cables and also tried it on a pc monitor and another tv and they all have the same issue!

Think the HDMI port itself is faulty but will be really annoyed if i have to send it back to get it fixed already as its only 5 days old!

Any help would be appreciated! 

SETUP

I7 3770 3.4GHZ

8GB Ram

NVidia Geforce 660 1.5GB