Arduino with Amtega32u2 usb to serial converter

Hey, I have an arduino clone with 32u2 on it for usb to serial converter. Recently, the board started to refuse uploading sketches. I'm planning to refresh the bootloader of the usb to serial converter. However, I cannot find the combined dfu usb serial hex file for 32u2 which means I have to compile it myself. However, the combined dfu usb source is not provided and it couldnt find it anywhere. Can someone help me get the combined dfu usb source?

Now to clarify certain things. To reflash the chip and get it to work properly, I need to be programming the bootloader area of flash, right? A simple ordinary flashing using an ISP wouldn't work, right?

Thanks.

Hi,

Nick Gammons programmer can program Atmega 16U2 chip as USB Controller over ISP. I don't think I saw an Arduino with 32U2 as USB Chip.

This is the problem with China clones. My Nano clone stops working, but fires "NON GENUINE CHIP DETECTED" over Serial.

Regards, Mav

But I things'll be fine if we get hold of the source files.