Hp notebook zd8000 wont power on

when i plug in the power cord and press the power button the only light that flashes is the battery light, it only flashes for a few seconds then stops. the light on the ac adapter is on so i think the power ac is good because if it wasn't i don't think even the batter light would work. without the ac pluged in the battery light does not go on. Do you think i should order another plug and see if that is the problem. my laptop is 3 years old.