Hi Rahulgore,
I doubt that it's the battery because if it was, then the laptop should have turned on when you directly plug the unit into the main outlet without the battery.
For further assistance regarding your concern, please contact the Sony offices/Sony representative offices nearest to your place of residence in Asia Pacific region http://www.sony-asia.com/countryselector.html?hpid=countryselector:AsiaPacific. Due to proximity, they are in a better position to respond to your questions or concerns.
Regards,
Jen
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