I knew there was a good reason to come to this FORUM... I took a tip; "thwacked" the DT402 controller in the palm of my hand, and "shazaam"! Looks like I'm back in business. I think it would be smart to purchase a back-up DT402 anyway from (FORUM-recommended) TrainWorld for @$148...
Thanks guys
Buying a second controller is always a good idea. Digitrax repairs could and do take up to a month (in my case) to get it back. Not being able to run your layout for a month sucks.
You should have posted this with your original post. Otherwise anyone looking at that thread will never know your success story.