Laptop keyboard not working properly

I have Lenovo Ideapd Y510 laptop with windows 7 and its Lenovo Laptop Keyboard has suddenly stoped normal working. Its few keys are working and other are not as they should. As you can see in image the keyboard has a function key of left bottom corner and you all knows on pressing fuction key the secondary functions of keys gets activated.



The Lenovo Laptop Keyboard is behaving like as if I have pressed FN key, I mean when I press left arrow key then instead of moving cursor to left the volume start dicreasing because left arrow key also works to reduce volume on pressing FN key then left arrow key. When I press U key then insted of typing U it types 4 because U key behaves as number key 4 on pressing FN key.



What I mean to say here is that Lenovo Laptop Keyboard is functioning like I have pressed FN key. All keys are doing their secondy tasks not primary, the keys which do not have secondary option are working fine.



Is it a normal issue that could be fixed at home or should I take it to a laptop service center?