Electronic – arduino – Computer can no longer see Arduino; possibly burned out

arduinoserialusb

I have an Arduino UNO R3. I was working on this excercise and I could not get the servo working. I thought the USB port may not provide enough power, so I plugged a 9V/1A adapter into the barrel jack as well. I also pressed the reset button. I noticed the edge of the PCB between the USB port and the barrel jack getting hot, and I unplugged the Arduino.

When I plug the USB cable in now, the "L" and "ON" LEDs light up, but there is no activity on the RX/TX LEDs and my computer does not recognize the Arduino (no /dev/ttyACM0 shows up). Looking at the edge of the PCB, I see a bit of a white powdery residue where it was heating up, although I am not sure if that was there before.

I'm worried that I may have burned something out in the PCB. I may have had the 3 pin header for the servo misaligned. Can anyone offer me some insight into what may have happened?

EDIT: Here is the edge of the board:

Arduino.

Sorry, I've already scraped off a bit of the powdery stuff, so it is harder to see now.

Best Answer

It might be possible that you fried the fuse or the regulator on it. To verify that you can use a multimeter. There is a regulator which looks like this:

enter image description here

You can see if the pins are short(which means it might be busted). You should never power a servo as mentioned above by Chris, as it can draw too much current. If the regulator is fried, you should give it a shot to replace it, instead of spending money for another one. ALso try connecting it to another laptop to see if it is detectable.