Hi , I am using adafruit motor shield version 1.0 with arduino mega 2560 . After a while when I connected external 12V 2A power supply through power jack of arduino mega2560 board , the board got extremely hot and stopped to work and in this time another 12V battery was connected with motor shield as external power source . After that arduino mega2560 doesn't respond and not recognized by computer either ( not even the existence of any usb device , when I connect with pc I found nothing ) .
I have checked the on board voltage regulator , it works fine . while I connect arduino mega2560 with usb cable to my pc , the power LED lit up , but arduino mega2560 doesn't respond . The chip ( ATmega 2560 ) getting hotter slowly . What can I do to troubleshoot ? Please give me any Idea.