Sapphire Radeon HD5770

[slowlearner]

Hi All

I'm just finishing a first build and am trying to fit a Sapphire Radeon HD5770 GPU to a Gigabyte GA Z77 D3H motherboard with a Core i5 2500K CPU. I installed it in the top PCIe slot, plugged in its power supply, plugged in the DVI cable to the monitor and switched on. The monitor does not respond - just a blank screen with no signal, although the card is apparently functioning properly (lights up, fan operates). What am I doing wrong? How do I load the driver with no screen? Is it a BIOS problem that stops the graphics card from being seen?

Help (in simple terms as I am a practicing idiot) would be much appreciated.

[autotech]

Can you try a vga cable? Does it even post bios?, That cpu has inteagrated graphics can you put the DVI  cable into the motherboard and does it show then. If it does then go into bios and change it to show thru pcie slot and not the onboard graphics.