had that problem with mine last night mate!
trying to fix it in the pitch black
great lamp once running
had the same problem not so long ago puts a downer on the nite
but as you said when working cant beat them
it is a good lamp mate but the wirering on them is very poor so if i was yoo i would re wire it so yoo are not out in the feild went it goes wrong
and all the best withe the bitch