Power problem

Hello,
I have a great quality laptop. I have been using it for over 3 years now. I have a strange problem with it. When I push the power button, it doesn t turn on. I press it again it doesn t turn on again. I keep on pressing the button repeatedly; the charging light and the power light flashes for split seconds on every 2 to 3 times i press but the laptop still doesn t turn on. After so many tries of pushing the button, the laptop finally turns on. The laptop charges only when it on. When it is off, ot doesnt charge. All these attempts of turning on described above occurs only when the charger of the laptop is disconnected. When connected, the laptop not only doesn t turn on, but also the charging light and the power does not flashes at any instant. What exactly is wrong with this laptop? Can someone Plz show me the solution to this problem and the way to fix this problem. I ll be grateful.