BMM80 MEGGER FAULT

[challie2]

IT WORKS ITS ALIVE!! ITS ALIVE!!!,
I had a scan over the entire board which comes in 2 pieces, a control board and a switching and analogue board, turned out to be nothing more than a piece of solder dropping from somewhere, causing a short between 2 pins, i think what it was doing was providing a high signal to that pin which in turn feeds to another pin on another IC that when hi controls another function, so it was switching modes between the 500V &1kV its still a little bit glitched but works without fault so happy. turns out as will that the drawings used by Avo to make the Megger is on the exact same CAD platform and design style as railway signalling drawings which is called Bentley 

Thanks Everyone for your support!