Last night I powered up the electrics just for fun and all works fine. I switched things off and then on quickly once and the ADI started slowly cycling back and forth between full nose-up and full nose-down at about once per 3 seconds. It went on like this for a minute or so until I shut it off. When I turned it back on it behaved normally. Any ideas on what this was all about? Obviously this is about as bad a failure mode as you could want.
