Yes, I was lucky there, not normal for me ;)

hopefully as as it has put up with that abuse, and the fact that I was cutting with the panel door open too, it shows that the rest of my efforts re shielding and grounding were all beneficial and good ones :)

my original plan was to strip the guts out of the PC and fit it all in the cabinet but it was not big enough, that would likely have worked ok too, oh well live and learn;)

thanks again for all the help.