Black screen after windows load when second GPU is installed

[HindSeeker82]

Hi guys!

So I recently got myself some 980 classy's, which meant I had my old 780's lying around.
I decided to give them to my roommate to play with, but we've run into some odd issues when trying to get the cards running in his system.

Basically, as soon as the second GPU is hooked up and windows is done loading, we get a black screen.
This doesn't seem to happen when there's just one card installed, no matter which PCI-E slot it's plugged into.

The things we've tried so far to debug the issue:

Card nr 1 in PCIE slot nr 1: Works fine
Card nr 2 in PCIE slot nr 1: Works fine
Card nr 1 in PCIE slot nr 2: Works fine
Card nr 2 in PCIE slot nr 2: Works fine

Both cards plugged in: Black screen after boot
Both cards plugged in (Swapped PCIE slots): Black screen after boot

It seems to be a driver related issue, since booting into safe mode works fine, as does booting into the OS regularly after I've removed all Intel and NVidia graphics drivers.
As soon as I install the Intel VGA driver again though, I will get the black screen unless I boot into safe mode.

Trying to install the VGA driver while booted into the OS regularly will crash the PC while the driver is installing.
Both the Intel and NVidia drivers will install fine in safe mode, though after installing them successfully I will inevitably get the black screen after booting windows normally.

It seems the only way I can get regular windows to boot, is to boot into safe mode, wipe all the drivers with Display Driver Uninstaller, and reboot.

I've just done a format on the PC, but the problem still remains.

I can honestly say I'm stumped on this one.
Do you guys have any ideas?

His system:

CPU: Intel i5-3570k
MOBO: Asrock z77 Extreme4
PSU: Corsair RM850, just bought it today in order to be able to run the cards.
Storage: Samsung 830 250gb SSD, 2 WD 2TB drives

His system was running fine before, with a single ASUS GTX770

[Mick Naughty]

Is he on his boards latest bios? What port on which card are you using to connect his monitor? Have you tried with and without the sli bridge?

[HindSeeker82]

- We've tried both of the DVI ports on both of the cards.

When both cards are plugged in, only the card in the second PCIE slot seems to output video though.

This seems to be independant on which card is actually inserted in the slot, it was the same when we swapped them in their slots.

 

- We've tried both with and without the SLI bridge, no difference there.

 

 

I'll try and update to the latest bios now, that something I hadn't tried yet.

[HindSeeker82]

Updating bios did not help.

[Mick Naughty]

Well you should only be using the top card to connect monitors when it comes to sli being enabled.

So after windows loads you mean the splash screen not the welcome screen right? Do you still hear it through the speakers?

[HindSeeker82]

The top card doesn't output any video when both cards are plugged in.

The windows logo screen with the little circle of dots going around completes successfully, then before the next screen it just goes black and nothing happens.

 

I've tried this both with auto-login enabled and disabled, so it's not like it's just not outputting any video. There's nothing on the speakers either.

As far as I can see, it's actually frozen right before you'd get your login screen.

[Mick Naughty]

Reset cmos and if you can get into the bios, reset defaults and if the board has the option, flash the bios.