I forgot how, but, the D1000T will tell you which wire pair is the problem (it was in the installation manual). In my case, it was a wire pulled out of a pin in the elevator servo DB9. Since the servo is about the hardest to get to, it was, of course, the one with the problem! If your stuff is like mine, skip to the hardest to reach part first.Caution message on my D1000T, 'standby network error'. What would this be?