hardware - HP ProLiant DL360 G6 won't boot

I have an hp proliant DL360 G6 server that was 1 year stopped..
I turned it on last week and it was working just fine. So i left it working during the weekend.
On Monday when i returned i notice that it was on suspension mode. I tried to bring it back to life but no results.
So i turned it off by pressing the button, when i turned it on again it wont boot and no post. I only gives me a long beep continuosly. I have changed the memorys, processor and fans are runing fine. The internal leds on MB are all green but i have a blinking green led next to the memory slots 1. On front the power button led is green but the health led is blinking red.
Note: I have changed the hard disks when i turned it on the first time one year and it was working perfectly fine.