Why doesn't my laptop start up?

Cannot turn on my computer!

Hi!

Cannot turn on this laptop.

If I plug it in with battery in - status LEDs are indicated as:

Power/Suspend LED - lights up red;

Battery Charge/Discharge LED - bliks red;

If I plug it in with battery out - status LEDs are off;

When I try to turn computer on in both cases Power/Suspend LED turns on green for a half second as soon as I release the power button and I can hear as ventilator span on, but after half second it all turns down and returns to previous positions.