And it started working again.......thank God!
Here is what I did:
Removed the back cover. Did it with my finger nail. I was looking for some place to insert my nail in and the cover actually popped out a bit. Form there onward, it was a piece of cake.
Disconnected the battery (checked ifixit website for that).
Pushed the power button and it turned on.
Battery is at 100% coz it remained on charge overnight.
So that was all about resetting the battery.
Thanks a million to everyone who helped.