QUOTE ( any suggestions, EM?) so I look forward to finding out what your cunning plan is...
Well, you could always use a variant of a scheme I devised some time ago to cure an elusive short in my old Scalex track - I removed all of the electrical connections to the affected lane, attached my auto battery charger and turned it on! A small report and a brief flash denoted the vaporization of the offending object and. after reattaching the wiring, all was well.
EM