It's been a while since I've posted on here, but unfortunately Ive had new problems with the Zig charger which I can't work out.

Zig does not work on hook up - orange ON switch does not light up. It worked fine for 3 weeks touring Spain until we got to Barcelona a few weeks ago where hook up wasn't earthed - don't know how significant that is? Take it trip switch has nothing to do with it as it remained on.
Whilst touring the fridge worked and LBatt charged
Ive looked at manuals and threads on here but haven't seen a similar problem.
All fuses checked and are ok.
Are there any ways to check if the zig is working? There's a 240v plug in at the rear - is it ok to plug that into house mains?
Cheers as always appreciate any help.
Ive a JAL side conversion (2012).