Some keys on keyboard is not working

mksamadnet - Dec 13, 2016 at 12:55 PM
I have a dell inspiron n5110 laptop. Certain keys in the laptop had stopped working recently.
Earlier days long pressing on the keys was making it active. But now the keys are fully dead.
I have purchased new USB keyboard by thinking that the problem is with my ps2 keyboard. But the same keys on the usb keyboard also not working.
What should be the problem?