My acer 5431 laptop turned itself off

Hello,

my acer 5431 laptop turned itself off now it wont turn on no pwer light comeon nothing i tried ti power up with the battery out and onlythe mains in did not work i tried removing the battery and power leed pressing the power button for 30seconds and then put the power leed back in and tried to power up and again nothing can anybody help please!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! im desperate