Opps. My Uno took a shot.

Not sure what I did, but I cratered one of the chips on my uno. Weird thing is, it seems to be working. (or at least it lights up and I can still upload code to it.)

Can someone tell me what the chip is in the white box in the attached photo? Got smoke and a small divet from the center of this chip.

arduino.jpg

Well, so maybe it doesn’t work as well as I thought. Ran the standard Blink sketch and it works, but the LED never completely turns off. Instead, it alternates between full on and dim.

Still curious about what this chip is, thought. Any idea?

Op amps.

Arduino_uno_Pinout.pdf (156 KB)

Arduino_Uno_Rev3-schematic.pdf (81.4 KB)

A double opamp. Half of it drives an onboard LED, connected to pin 13. The other half switches a mosfet that turns off USB power when Vin (external power) is above 6.6volt. Leo..

Ya - you can't use external power with USB connected now. You should probably pull the chip (clip it out), as they typically fail such that they draw high current and get hot and stress your regulator.

Your board is fine. Now you cannot power the board with ext power and usb at the same time (anyways this is never a good idea).