I am having a problem with the MEGA 2560 that have searched high an low for someone with a similar problem with no success. I have two 2560's that are used in tow solar tracker controllers. Several weeks ago I go to upload an new program to the 2560 and after plugging it into the USB on my MacBook Pro the MacBook no longer sees the MEGA on the USB. It is like nothing is plugged it. Other Arduino boards work fine so it is not the Mac or the driver. The Arduino program that was last loaded in the now bad MEGA is working fine I just can't upload a new one. So I replaced the MEGA board with a spare. Today the spare now has this same problem. I am thinking that the ATmega16U2 has lost it's mind. I have a AVR ISP programmer. Is there a way to try and re-flash the program in the ATmega16U2? Has anyone heard of this problem?
Thanks
Kurt