Problem with two 4gb rams

[kostaskol]

Hello,
I recently bought a new 4GB ram. The one I was using was also 4GB and the system ran perfectly. However when I installed the second ram the pc wouldn't boot, although the fans would work. I tried switching the rams on the motherboard, tried using only the new one but nothing. Only the old one alone would work. So I thought it might be a power supply problem because it was 380 Watts. So I bought a new 550 one hoping it would solve the problem, and yet still nothing. The system just won't boot with both installed.
My pc specifications are:
CPU :Intel core 2 quad @ 2.4GHz
GPU :MSI Geforce 630 4GB
Hard drives : 2
OS : Windows 7 64-bit..
Thank you in advance and I really hope I will be able to solve this problem.

[hey]

It's dead, rma it.