I'm running a Celeron G1630 (LGA1155) on a Gigabyte Z77-HD4 with 4Gb, using BAMT 1.2.  Mobo has a 16x pcie, a 4x pcie and two 1x pcie slots.  I have two psus chained together, both Corsair HX850s.  PSU1 powers 2 Sapphire Radeon R9 290, plus the mobo and all 4 USB risers.  PSU2 powers just 2 Sapphire Radeon R9 290 tri-x cards.

The system will run with 3 cards, but not with all four (it sits on black screen after BAMT loading screen and before the desktop).  I've tried various jumpers on the pcie 1x and 4x slots, and no effect.  I've also tried booting into safe mode, with no effect.

Really trying to get four cards up on this board, but I'm starting to lose hope.  If anyone has any thoughts, or knows this board, I'd be most appreciative.

Thanks\