Times like these make me glad I never modded mine. When mine broke down about a month ago Microsoft sent over a guy with a brand new one in four days.
Thats what I call good customer service.
I know thats not helpfull, if you live in Delhi Palika Bazaar is the way to go. But even the guys who repair it dont provide any cover if it breaks again (and it does). You are better off selling the broken one and getting a new Core.