New computer builder need's your help

I'm a first time computer builder that desperately need's your help. I list my components first. 1. NZXT Tempest EVO case 2. ECS A790GXM-A V1.0 motherboard 3. AMD Phenom 2 965 125W TDP BE cpu 4. Corsair TX750W psu 5. Crucial Ballistix PC6400 DDR2 ram 4 x 2gb. sticks 6. Seagate Barracuda 7200.12 1.0 tb. hard drive 7. Samsung SH-S223C DVD-RW's x 2 8. XFX Radeon HD5770 1.0 gb. video card 9. Hauppage WinTV HVR-1800 tv tuner 10. Zalman CNPS 9900 ALED heat-sink This is my 3rd of this motherboard. On the first 2 motherboards I removed the white plastic piece with the small holes in the area on the motherboard where the cpu goes. After I installed both the Phenom 2 965 cpu and Phenom 2 920 cpu on both boards nothing cpu wise would work to allow me into the bios. I RMA'd both boards back to ECS. I just reieved my third motherboard and need to know if I'm supposed to leave that white plastic piece where the cpu goes on the motherboard and install the cpu on that plastic piece ? I was told by ECS support that the cpu slot on both RMA'd boards was bad.