Hi PARITOSHUPADHYAY 

Thanks for writing to us. 

When did the issue start? When you toggle the caps or num lock do the LED's respond? 

Please disconnect the charger and then remove the memory modules and test the machine with one module at a time. instructions can be found on support.euro.dell.com--enter the tag#--submit--manuals.

Do provide us your system tag#, email address and name via private message,by clicking on my name in blue and then select send a private message

Regards

Hi We are awaiting your response.