Thanks for the replies. It was used on Tetrix and this is its second season. Other side looks like new, date stamp is 2011. No charring on the cables or the ports. We use a surge suppressor (
http://www.l-com.com/surge-protector...ith-pigtail-12) between the NXT and Samantha.
I think we have decided there must have been a short on the robot that put voltage on ground - Samantha went because it was the weakest link.
Rewired, shortened, tightened and isolated wherever possible. Working fine on the replacement module.
Thanks again,
Ron