How to get Arduino Mega 2560 Rev3 into DFU mode?

Something is wrong with my Arduino Mega 2560 R3. The Serial port option in the IDE is greyed out all of the time and the computer detecting anything when I connect it via USB. I did some research and found out it might be the fault of the 16U2 chip drivers. So I need to use flip and go into DFU mode to fix the problem. Only problem is I can't find any clear instructions. The one on the Arduino website is for the R2 version. THe R3 is a bit different and I'm not sure how to proceed. Please help :frowning: :frowning: :frowning:

I have the exact same problem. I'm trying to use the guide here but when I try putting the mega 2560 into DFU mode I get the error:
dfu-programmer atmega16u2 erase
dfu-programmer: no device present.
make: *** [dfu] Error 1

I assume this means that I didn't get the Arduino properly into dfu mode