Yep as in work return. I have unfortunately already requested a replacement from Amazon and I can't change it, otherwise I'd have followed your advice. I'll let you know how the next one turns out!Earth as in work return rather than mains earth?
I suspect if there had been any contact with damaging results you'd see signs of arcing and burning. The wiring looks rather naff.
TBH since this is the second of these you've had die almost immediately, and it's a £100 welder, I'd send it back and try and get your money back as you have no confidence in this model. Then get something likely to be better, which might well be second hand.