EliteGroup (ECS 915PL-A2) Motherboard "hd2600" Questions

I have installed a new PCIE Video Cards on my P5VD2-MX, (Powercolor ATI Radeon HD2600 XT 512 DDR3) ... but games like Assassins Creed, Rainbow Six Vegas 2,... only some part of its audio could be ...

no power I have installed a 915PL-A2 motherboard and built onto it a Radeon HD2600 pro Graphcs card. When I switch it on it only it starts for about a second and then stops. Any Ideas please? Hi, Make