I got the problem rectified. the reason for this was already discussed above.. yes it was due to a short circuit of a capacitor, which is used to boost voltage for LCD panel. The damaged capacitor shorted the line to ground. I replaced it with 4.7 uf SMD capacitor(i had that value only... you can go for greater value also[There is a little flickering for me, so go for greater value])..... I took the risk since my warranty period ended one year before itself and also I am an electronics engineer.
Now it works like a charm.
if your warranty period hasn't over or don't have any professional skill or knowledge on this in prior, pls don't attempt