I have an Arduino Mega and it was working correctly until 1 day ago. I don't remember if I did a short or something but the problem is that now does not work. If checked Drivers, the usb laptop and the cable so I'm pretty sure is a board problem.
The problem is that when I connect the board to the USB there is no communication. I connect it and led "L" blink twice (so it is powered) and no more, TX and RX are like dead. I have tried to follow the "Loop-Back Test Instructions" and I don't know if I doing it correctly for Arduino Mega. (" http://arduino.cc/forum/index.php/topic,73748.0.html ")
In 3, "Connect Jumper from RESET to GROUND" is the same to maintain button reset pressed?.
And number 4, jumper from TX to RX, I have to do it in all of the Arduino Mega TX and RX's pins?
Thanks!