Dell Inspiron 15 N5010 beeps on startup continuously and wont sh

Hello,

I have a dell Inspiron 15 N5010 which is about 4 years old. It was working properly, but suddenly it went off and when I restarted it, there was nothing which appeared on screen, but there was a beep sound which went on until I turned my laptop off. Even the startup screen didnt appeared during this. The power button lights up, fan is running, but the screen is not coming up.

I have noticed one thing also, if I put it on for long time, so that it gains enough heat due to constatnt running and then I restart it, the screen will come. and after sometime, the screen distorts and after few seconds, the laptop screen turns black and the beep sound appears which start crying until I turn laptop off.

Thanks in advance for any help that is actually helpful.