I have a Samsung SCH-N191, the phone turned off suddenly while i was using it once and it refused to turn ON again.
I sent it to the samsung repair centre and they said that its motherboard had been spoilt. And they said that it would be Rs. 5000 to replace it.
I wasn't my fault that the motherboard was faulty, i didnt even drop the phone. It must have been a faulty piece from the beginning itself. And Rs. 5000 is just too steep for a basic phone like that.
This should be included in the insurance cover.