Can't rewrite 8U2 bootloader

I have an UNO SMD board, and am having the same problems uploading while the serial port is active, that has been mentioned on this forum many times. The solution seems to be to load a new bootloader with DFU. I have followed the instructions, but when I do: "sudo dfu-programmer at90usb82 erase", I only get a " no device present" message. Since I have the SMD version of UNO, I assume I do not have to solder anything to the board, or touch any contacts other than the reset pin & ground pins. I am running Ubuntu 10.02. The serial port name is ttyACM0. The port does not go away when I ground the reset pin. This is a serious bug in Arduino, and I am getting desperate!


lsusb -v -d 2341:0010

lets see what version of the DFU you are running.

I have followed the instructions

Which instructions did you follows?

The lsusb command, as you wrote it, produces no output whatsoever! Yet lsusb -v does list an “Arduino Uno” device with those vendor and product IDs.

The instructions for updating the bootloader is in


You followed the "non soldering alternative" then?

Take a look at reply #1, it a picture. This will work with the SMD UNO also. I done it many times.

connect Uno to your computer via the usb port

  • Hold ATmega8U2 Reset to ground (wire 1)
  • touch "Normal" Reset to ground (wire 2)
  • Remove wire 1

cd arduino-0022/hardware/arduino/firmwares/arduino-usbserial/ sudo dfu-programmer at90usb82 erase sudo dfu-programmer at90usb82 flash Arduino-usbserial-uno.hex sudo dfu-programmer at90usb82 reset

unplug the Arduino board usb connector plug it back in.

Run the Arduino ide

It worked!!!

All it took was that detailed picture, and the very simple instructions - "hold here, touch there".

Thank you mrtaylor, and everybody who took the time to respond to my problem.


Your welcome

Great instructions; Thanks.

I'm running 10.10 Ubuntu and have reset (I think) as can be seen by the output if lsusb

Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 006: ID 03eb:2ff7 Atmel Corp.

Bus 006 Device 002: ID 046d:c521 Logitech, Inc. Cordless Mouse Receiver

When I try and flash, though I get an error

llist@LeosLinux:~/tmp/Downloads$ sudo dfu-programmer at90usb82 erase llist@LeosLinux:~/tmp/Downloads$ sudo dfu-programmer at90usb82 flash --debug 1 Arduino-usbserial-uno.hex Error parsing the line.

Something went wrong with creating the memory image.

I'd appreciate any help/pointers to resolve this


I've found the problem to be a corrupt file.

All working now.