Hello! I have a RUMBA board for my makerfarm printer. I have had problems with the 16u2 before, causing my printer to be an unknown USB device. I was able to fix it, but now it is back, and it is worse. When I plug in my RUMBA, the power light turns on, and LED1 flashes twice, and that is it. I can sometimes print from it, although it also boots into a weird "waiting for user mode" in which nothing works about 4/5 of the time. My computer doesn't even see anything is plugged in, and the RX and TX lights don't flash.

Could this be a 16u2 error, or even the bootloader? I have an Arduino Uno so if i need to I can reprogram the rumba I think.

This is really frustrating so help is really appreciated.