i think this problem is the same world over, the thing is the EC case is while we are busy pulling cables for power we pull in the V & D side as well. it only needs 1 dip stick to put the V/D in the same compartment as power & that runs knackered, now days i install systems to a frame/DP, if the phone works there but not on the other end of the run (tough SHIT) not my problem. However i would charge £75 an hour to resolve the fault or to put a new one in.