I've just had a Pershing MF unit turned back by Tamiya America because "they did not have the ability to repair it", they offered to sell me another for over $100, but it isn't the first time that particular MF's flash module had gone bad (the first time I had posted it to Tamiya Japan who fixed and returned it for a fee). I've been wondering about the same time - a microswitch that is triggered by the recoil cradle. Its doable, I suppose, but timing is everything.