SLI Black Screen... Power Supply Problem?

[obsol337]

I bought:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341052

Thinking that it would be enough to power 2 GTX 560's in SLI. Every time I try to enable SLI, my screen goes black and will not recover until I remove the Nvidia drivers. Both cards work fine singly, and I tried changing my Nvidia drivers to the 290.36, the 285.62, and I'm about to try the 280.26 and the 285.79 drivers as well, but I'm not holding out hope. According to some calculators, I should only be pulling 500w or so, so I figured 750 would give me plenty of headroom. Is it a power supply? Are there other things I can try first?

i5 2500k @ 4.2, down to 3.3 for testing.
Maximus IV Gene-Z
OCZ ZT 750w


Thanks in advance.

 

[alyoshka]

Have you tried changing the SLI bridge between the 2. If not, try that out and see if it works.
Usually this problem is faced by people using a defective SLI bridge try laying your hands on a new one and use it to check.

 

[vitornob]

This PSU is more than capable to support your SLI (it could power up even SLI GTX 570)

Try to use another SLI Bridge

 

[obsol337]

Grabbed a couple of SLI bridges from the local computer shop for testing purposes. No dice, SLI bridges are not the problem. Thanks for the ideas though. Still don't know what's going on.

 

[alyoshka]

Try this, exchange the Places (Slots) of the 2 Cards, put the top one in the lower slot and the lower card in the top slot.
And make sure that you have them placed in the correct PCIe Slots. Unless this is the mATX board that has just 2 PCIe slots.