A simple check w/ a multi-meter will tell the tale. (But I know it happened, and our Ohmmeter did not lie...There was resistance present). Removed that screw, no resistance present. No more frame grounding issue
All I can tell you is; Removing the very unnecessary grounding screw on the blunt flat end of the CRIO cured up the frame ground issue immediately. The CRIO is powered by a regulated 24V power supply from the PD Board and am told by many since the incident (we have not before or since melted any of our Anderson connectors 2.5 minutes or hours), should never touch the frame (or ground to the chassis). That screw is chromed and unpainted. (And now completely gone from all of our Team CRIO's).
Go to this link; Scroll down to the Pic below "Attach To Robot" (where they instruct teams to attach your completed Control system boards to the robot).
http://wpilib.screenstepslive.com/s/...m#!prettyPhoto
Now, make that pic larger using the symbol lower right, look at the flat end of the CRIO in the left part of the pic. You will see the grounding screw I am talking about on the right hand side. (And that one is actually very close to that frame itself though not actually touching it in the pic, but could very easily later). Ours was caused by a hasty reinstall by 2 very tired students is all.
http://wpilib.screenstepslive.com/s/...dware-overview
"The PD provides a regulated 24V power supply to power the cRIO, a special, regulated 12V power supply for powering the robot radio and a 5V power supply for powering an Axis camera."
Are you absolutely sure it could not possibly have caused that? We know why that screw grounded to frame, and we know it cured up our issue, that bot still sits in our shop and still runs today. And did the rest of that day.