The complete firmware reload did the trick. It did not detect the Pronto, so I pressed the Troubleshoot button. As instructed, I pressed Home-Menu-Page Up. Then I pressed Firm1, Firm2, & Firm3 within 2 seconds, for at least 2 seconds.

This was not discussed anywhere, but once you have the Application Download Mode on the pronto screen, you open the TSU9600Updater (download from Remote Central), and follow the instructions.

The Updater could not communicate with the Pronto on the first few tries. It finally worked on the 4th or 5th try.

Thanks to everyone for the help! I don't have a brick after all!