Arduino Uno 16u2 fried?

Hello everyone :)

My Uno (genuine R3), which has worked fine for over 2 years now, suddenly does not appear in the device manager anymore, not even as an unknown device.

  • Atmega 328 was removed a while ago, since I'm using the Uno as a programmer most of the time.
  • When connected to USB, "ON" and "L" Leds light up, the "L" led sometimes blinks randomly or appears very dim. Weird.

I think that the 16u2-Chip is either fried or has to be reprogrammed. I already read quite a few articles about doing that, but it seems as if the 16u2 doesn't want to enter DFU-mode.

So is there an idiot proof way to determine whether or not the 16u2 is fried?

lg, couka

No idiot proof way. But you can attach an ISP programmer, or use another working Arduino as a programmer by loading the ArduinoISP sketch, connect it to the ICSP header near the USB port, and see if you can burn the factory firmware back on the 16U2. IDE includes avrdude that you run to do that, and also the firmware hex file is in a subdirectory of the installation. If it loads without error that would be a good sign. If the board is not getting hot when plugged in that is also a good sign.