New PC build - black screen, all fans etc are working

I have just assembled my first PC. I turn it on (motherboard led is on, the led's on my ram light up, my cpu cooler's fan starts up, my case fans are spinning, i can open my cd drive) however my monitor remains in standby (yes i have checked and it works)

I dont reach the bios.

I have tried reseating my gpu (4870) no joy, i have tried the other pcie slot again, no joy.

I have tried with one stick of ram and with two

Any help?

Please help.

Thanks!

I didn't find the right solution from the Internet.

References www.gamespot.com/forums/pc-mac-linux-society-1000004/new-pc-build-black-screen-all-fans-etc-are-working-26527813/

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