PC powers up but no input to the monitor

[HBM]

Hi Guys,
I recently undertook a PC build and its done, however the PC powers on, but there is no BIOS input to the monitor. Any ideas? The mono, fans, GPU all power up but no input.
Help please!

 

[HBM]

Thanks for the replies. I tried pooing into it but the HDMI port was too small! Oh and aiiting on it broke the case. The cable is connected into the mother board but still no luck.

 

[HBM]

OK thanks anyway