as title states...new UNO board coming up as atmega16U2 DFU in device manager on Win7 and also Win8.1. I have read on here for hours, and googled....no luck.
It sounds like the 16u2 is starting in DFU mode (normally used to update firmware on the 16u2 used as a usb<->serial adapter.... though I can't say I know why that would be happening.
thanks for reply, you may be right. I tried shorting the two pins for DFU toggle and the ATmega device drops from the device manager. problem is nothing else pops up/in.
The ATmega16U2 USB-to-serial chip is probably running the Atmel factory DFU bootloader (only) and the USB-to-serial program was not loaded on the board by the board manufacturer. You could probably either return the board and get a good one, or solve the problem yourself by using DFU or ICSP to load the USB-to-serial program on the ATmega16U2. The program is included in the IDE installation and is called Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex.
No, there is no parallel port involved. Just use the DFU bootloader on the chip to upload the USB-to-serial firmware onto the chip. I'll bet you can find a tutorial to upload using DFU. You can skip the part about putting the chip in DFU mode by shorting the pins, because your chip is permanently in DFU mode until it gets some firmware on it.
I advise contacting the seller of the board and explain to them they sent you a bad board, as it does not have the USB-to-serial firmware loaded on the ATmega16U2. Some sellers have been known to send out a new board and tell you to keep the bad one. Or perhaps they will send you a good board in exchange for the bad one, and save you the trouble of uploading the firmware.
Thanks all that replied. I ended up sending it back to the seller and getting a replacement. All is well now, and my son is enjoying working with the kit.