Sorry, I dont know I should ask this question or not!
I supplied nano with 42V for 3-4 seconds with no J48 jumper.
After that it is not turning on (Green LED is OFF always) with anything. I tried 5V micro-usb with no jumper, 5V barrel jack with no jumper and 5V barrel jack with jumper.
FYI: I observe now blue LED of my 5V-4A AC adapter is blinking.(Before, when nano used to work, blue LED was ON always). This makes me think that now nano is drawing more current, without turning ON.
Is there any thing can be done apart of arranging a new one?