cdb wrote: > From an academic point of view does any one have any thoughts on > what could be the most likely cause? Without a schematic, probably not much. > I have no choice in the oscilloscopes at my disposal at work. There are always choices. However, you could rig up your own high voltage probe for the existing scope. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .