My Dell Inspiron 15r starts up but screen is blank

Hi guyz,


My dell inspiron 15r sometimes turns on and works perfectly fine and the other time when I press the power button the fan and lights are working but the screen is blank. And if I tries switching off and switching on for sometime, the screen turns on and works completely normal. For this to happen I will have to switch off and on for around 10-20 times. And its really embarrassing in front of others. And when shutting down it always wont shuts down completely, and stuck at a blank screen. I will have to manually hold down the power button to switch off the laptop.

Please tell me what to do ..

Thanks.