First things first, this set up was working this morning with the use of a different motherboard. So yes the power supply can handle the two cards. Both were working and I was happily gaming in Crossfire mode.
What i've done so far: I've updated the Bio's, it came with 1.1 noticed the second card wasnt being detected on windows device manager, so I updated the Bio's to 1.7 same problem, rolled the bios back to 1.4 same problem. Cleared the bio's Same problem.
I then removed both cards and tried them one at a time. First using the top slot and yes the both worked, I then tried them both on their own in the second slot. Neither worked.
I'm at a loss and i'm sure I've probably over looked something basic. So I need fresh eyes from people a lot smarter than myself to help me out. I REALLY don't want to have to send this back as I've wasted an entire day on it already I dont want to turn this into a week long disaster. This is my 4th computer i've built but its the first time i've used a MSI motherboard and i'm unfamiliar with it.
Do you have the newest drivers installed for those cards? When you install them, do it with one card installed. Once the drivers are set up, add the other card. I guess there could be a BIOS setting for your pcie lanes. I have never had an MSI motherboard, so I am unsure on that.
Already done the drivers. I had trouble on a build a few years back with crossfire and learnt to install them as you suggested as a matter of course. I've had a look through the Bios for PCIe Lanes but haven't come up with anything. Like i said im new to them so I may have over looked something.
@dextermat I'm hoping i'm wrong it is under warrnty as I only received it today. I just hate sending things back because it always turns into a massive saga for something that should be so simple!
If the slot is dead, then its dead, no miracle cure for that. However it could be the CPU/ CPU socket like alexoiu mentioned. Some of the pins may not be touhing the pads on the CPU, the pads for the second PCI lane that is. As long as the socket looks good send it back unless your happy gaming with one card.