[VashonRobotics]

Towards the end of our season one of our teams had the same problem. We recorded the problem with a video camera following it around on a practice field until it failed. Then we played back the video and discovered that the Samantha module lost power for a brief moment - all lights went out. Then it came back and was rebooting. In the meantime the NXT was stuck on the last command given so if it was turning then it just spun in circles. Sometimes when the Samantha module came back up and connected to the FCS again control returned and other times it didn't. The problem was easily duplicated over and over.

The Samantha module's power was coming from the power buss on one of the motor controllers. After careful inspection we found many of the wires connected to the motor controllers were tinned. This is bad. We found posts on Delphi and Internet that solder can deform or (cold creep) over time and become loose when in a clamp connection. After going through and cutting off all the tinned ends and inserting bare copper and clamping that down in all the motor controllers the problem could not be duplicated and this problem never happened again for the rest of the season. So our conclusion was that this problem (at least for us) was caused by loose connections in the motor controller wire clamps.

Nice tool that helped us with this troubleshooting process was using video. We couldn't have seen that it lost total power without it because it happened so fast.