My TV doesn't see the HDMI on my PC!

[cronosus]

I bought today an Orion Pif22-dled full HD TV, specially to use with my computer (wanted to have a monitor to connect to more devices). The problem is that when I plug in the HDMI cable into my PC, it doesn't recognize it! It says that there's no signal. The cable is connected properly, the monitor is set to HDMI and it even detects the cable,but I don't see anything on the screen. What could be the problem? My graphic card is an Sapphire R9 270 Dual-X OC, mentioned the name in case it could help with anything.

 

[ffg7]

do a detect in displays in control panel on the pc. select input source as "pc" in the menu on the tv.