advice needed please !!

[AjeeB]

i order 2 g5 video power cables and i have 4890 , what to do
i connect them both to logicboard and other side to vga card
but no screen all black and fan going crazy !!!! very fast
what should i do to get it back
cables come from OWC

 

[AjeeB]

I tried also power it with one cable not pair ! same result
if I put back my pc combination cables connected to DVD slot .. everything ok !?!
is that problem with LB or cables?

BR

 

[Mac Hammer Fan]

A 4890? Is this PC-card Mac flashed? Otherwise, it won't work.

 

[AjeeB]

yes it's PC ROM and flashed with EFI ! it's gigabyte 4890 1GB (flashed EFI)
if I take power via DVD cable no problem but not works with cables connected into LogicBoard
why?