I dont have a megger myself yet, i just got made redundant and I am contracting, and i found this for £20 so if it is not repairable then i havent lost too much i get a kick out of fixing things, as for the shocks College tutors lessons and fellow student pranks, engineering initiation rituals, work place pranks, and sometimes being plain dumb, especially after testing 500m 10mm 2 core cables and getting a zap from the residuals when i put what we call a condom (rubber tube basically cut up bleed pipe) over the cores too keep then protected and dry, otherwise the cable will be failed, need at least 50k ohm for railway signalling cable. Tested too 1kv.