Thanks, I did see that & wondered if it was a fuse. It looks like this...
I think it's normal as after some re-soldering of the DC connector, I managed to get it to the point where putting some weight on the plug made it charge. Blue lights on.
And then I also noticed after a while the Pronto settings screen would show it was charging even though the blue lights had gone out. That is probably just normal.
So I assume the fuse is ok but still not quite sure what's causing the problem.