Guys, First of all thanks to all those helpful tips from experienced users out here. I just got my Nexus 7 2012 wifi model from flipkart today and when I tried to power it on,it was dead.Battery was not even charging and then I opened the back cover and did the things you guys discussed here and after that still I couldnt power it up.Then what I did was that I connected the tablet to my laptop for around 45 minutes and then disconnected it and connected again immediately. By god's grace the charging icon appears and powered it on.But still the battery was not even charged to 1%.Suddenly I connected it to the charger and now everything just works great.Only thing to take care of is to keep that battery close to the inner wall and make sure the battery connector is secured.