Well, this thread having convinced me to try one (I've owned the TOP MkII and found it too big and cumbersome for airsoft use), I picked one up used.
I'm having a problem with the connection from the box mag to the gearbox; gearbox runs fine with battery hooked directly to it, and the mag winds when trigger is pulled, but gearbox isn't getting juice from the drum.
I tried unscrewing the cover on the drum feed and re-seating the contacts; the contacts in the mag well look fine. I can't find my multimeter at the moment to check if it's getting current to the contacts though. I can'