Connecting 3rd monitor from PC to SAMSUNG TV via HDMI

[Oudom Rith Hour]

Hello, My name is Oudom. I have a PC with 2 PC monitors which connected via DVI, and now I'm trying to make a 3rd monitor using HDMI from Decklink card to SAMSUNG TV, but it does not work at all. First my First HDMI cable showed NO SIGNAL from both ports, and I have search from internet many people said I might need to change to HDMI cable if its too old, I then bought another one (i'm not sure if its higher version) but from port 1 it still showed NO signal and I plug into port 2 of my Decklink card it showed nothing, its full of BLACK on the screen. So its still not working. or Do i need to set something on my PC after its all BLACK ? I'm lost. please help me

PS: I have tried to use this TV as the 2nd monitor via DVI, it works fine

 

[popatim]

Without know which exact graphic card or pc you have then I'm afraid we wont be able to help.