Crossfire Help!

Hello, I need some guidance here. I just received my new 290x card and put it in the second pci-e slot. I have a xfx 290x 1000/1250 and new card is a powercolor 290x 1030/1250. After installing new card I cannot use my first cards hdmi out anymore. It just goes to a black screen. So I plugged into new card hdmi and get video. I removed and reinstalled new drivers and can boot into windows. When I go to enable crossfire in CCC its not there. I checked GPU Dimm in bios and it only shows the 2nd video card in there at x8 which I know both cards will run at x8. It doesn't even recognize my first card anymore. Am I missing something here? I get no video at all out of first card. Not even to get to bios when 2nd card is installed. Please help..... My motherboard is a maximus vi formula/4790k with a ax860 PSU. I have a separate 8 pin and 6 pin line running to each card from the PSU for a total of 4. I don't think power is an issue. Im just not sure why it doesn't recognize card in 1st pci-e lane when 2nd is installed. The card in the first lane has been working great with zero issues since I bought it in March. This just started happening today when I installed new card

Does that board have a auxiliary power for the PCIe slots (usually in a molex or PCIe 6 pin form)? If so, you may NEED to use it in order to use multiple GPUs...check the manual if it has a molex (it does, at the bottom of the board)

Earthdog, it does and I already have power to it. I just tried pluggin into my first card again with same result...Black Screen not even able to see startup to get to bios. I am getting a error 62 which is PCH runtime error? I just plugged into new card to reply to you. I don't get it.

I was wrong on code....it is a B2 error which is Legacy option ROM Installation.....whatever that is

So when you take the 2nd card out the first works again?

ok this is crazy. So I took out the 2nd card and the first still doesn't work. I don't get what happened. The first card has been working flawlessly. I stick the 2nd in and no video from the first. I get video from the 2nd when their both in. After pulling the 2nd out the first isn't even recognized in the bios anymore and I get no video whatsoever. Could I have a bad pci-e x16 lane? I have no clue. I did have another one of these xfx cards back in march and had to RMA it because of black screen. I have been using RMA one ever since with no issues. First issue was today when I installed new card into 2nd pci-e lane. I have custom loop installed with gpu waterblock and its a pain and theres really no slack to move cards around. I probably would do more damage trying to temp it in. Im at a loss here

Only way to test that slot if by putting another card in...