Help with black screen problem

Thank you for your support, My Acer 3960-2900 has a black screen, i can hear the fan but can't hear the HDD powering up...earlier i unplugged the power cord removed the battery and installed new memory but nothing then when i plugged everything back in, all i had were 2 lights in front I wanted to be sure that it was the correct error that i am getting so i unplugged the power cord and the one light with the symbol of a battery went out now the only light remaining is the one with the symbol of a light bulb....does this mean it is still the mother board?

thank you
Bob