Hey, I have the same problem on a 6 fet eb306 Infinion. Happened ywsterday while setting up the bike for a ride. Plgged in the battery, worked for 10 seconds and quit. Opened controller and only 2 v on 5+. haven't looked further just switched to a 12fet and of I went.
Any ideas, I will look at mine next week, if noone has and idea what it is.
Didn't mean to hijack this thread, but I have the same problem.
Dan