Problems with R9 270x install

[FallingPiano]

I have been trying to install a pair of new R9 270x cards into a gigabyte GA-Z77-D3H mobo (fully compatible with the cards, I've triple checked). Power supply is 850W so that shouldn't be the problem. The computer boots fine on the iGPU, but as soon as the cards are seated and powered the computer will not boot. It will power on, fans will spin up, but nothing will happen--no beeps from the mobo, no lights, nothing else. I'm in the process of flashing the newest BIOS to the mobo to see if that has any effect on it. I also have made absolutely sure that PCI graphics are enabled as primary in the BIOS.

Is there anything else I can try or something I'm forgetting? Really hitting a wall here. Thanks for the help.

 

[El Tigre]

Try taking out the CMOS battery and reset the CMOS that way, sometimes, some mobos can be picky and just need to have their defaults restored. Give that a try first.

Then test one card at a time and see which one(s) are giving you the issues you are having now.

 

[FallingPiano]

I did that, the CMOS reset didn't seem to do anything and so far neither card has done anything. I tried an old backup card I had and it worked correctly, so I know the mobo/PCI slots aren't dead. I suppose one of the cards might be DOA or something, but since I have two of them that seems unlikely. Anything else it could be?

 

[FallingPiano]

Turns out the solution was a beta BIOS update (F23b). Thank you for the help.