Hi,
Today I rewired my project to move it from protoboards to the live set up. I know something went wrong in process because one my stepper drivers blew up (literally). Oops. Everything else appeared fine. I then noticed I wasn't getting much current out of the Mega's output pins. The voltage regulator was getting pretty hot, so I hooked up a power supply with a current reading and noticed that the Mega was pulling about 200 mA. I removed the DIO connections one at a time and found that the culprit was one line involved with the USB shield.
I have it hooked up the shield as shown in the image below (it's not stacked). The problem is the connection from pin 10 on the Mega to pin 53 on the Mega. Making that connection sends the current draw from 100 mA to 175 mA. Clearly that's not good. This connection is needed for the shield to function and connecting it does indeed allow the shield to function, despite this high current draw. I have tried a spare shield: same problem. It can't have been drawing this much current before, because I'd have noticed low voltage issues on other DIO lines.
Not sure how to proceed. Any idea why this pin is suddenly pulling so much current? Is it possible the Mega is damaged? If so, can I work around the damage and still use the USB shield or will I need a new Mega?
Thanks!
