Uno R3 with dead 16u2?

I seem to have a Uno R3 with a dead 16u2 chip on my hands.

The Uno was working up until about a week ago, and then I could no longer upload sketches via the IDE (Windows 7, 1.0.5). Windows doesn't seem recognize the Uno when I plug it into the USB anymore either.

I've got a ISP programmer (USBtinyISP), and I can program the Uno by the ICSP header OK.

But when I try to connect to the 16u2 header, I can't get a response of any kind no matter what settings on avrdude I try.

Can anyone suggest an avrdude command I could try to determine if the 16u2 really has died on me?

Thanks.

I've got the same issue and used the following to flash the 16u2 on a working uno r3:

avrdude -p at90usb162 -F -P usb -c usbtiny -U flash:w:UNO-dfu_and_usbserial_combined.hex -U lfuse:w:0xFF:m -U hfuse:w:0xD9:m -U efuse:w:0xF4:m -U lock:w:0x0F:m

(got that from Can not put Arduino UNO R2's atmega 16U2 into DFU mode - Installation & Troubleshooting - Arduino Forum)

that works fine (using a USBtiny) to flash the working uno r3 but my bricked uno r3 gives me the following response:

avrdude: initialization failed, rc=-1
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x000000
avrdude: Yikes! Invalid device signature.
avrdude: Expected signature for AT90USB162 is 1E 94 82
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
To disable this feature, specify the -D option.

avrdude done. Thank you.

so i suspect that i've bricked my 16u2 and can throw the uno r3 away :frowning:

Best,
gorenje