My laptop clicks on and off

Hello,


Hey i have had a series of problems with my laptop it is called a hp compaq laptop! we'll now another problem is when ever i turn it on it goes to boot screen then turns off then on then off then on ! all day until i take the charger out! it does no come on by itself only with that charger and when i put the charger in it clicks and then turns on and off ,<i already switched the battery so that's not the case? And opening the laptop is not an options cuz i don't no that much about laptops nor do i kno how to open them?! to complicated could anyone please solve this problem thankQ!!!!!:)