Thank you guys for your advices but I tried everything
two molex 4 pin plugged, 5970's in slot 1 - 3 - crossfire not runing
none of the 5970's is runing in slot 3 or 4 with 2 plugs hooked and pcie switches on .... vga led lights and no signal.
my 4870 512 just runs fine in slots 3 or 4 so not pcie slot broken