Found the solution to this problem here:
/g/QRPLabs/message/116094
Evidently the firmware file was corrupted preventing the QDX from initializing and making it appear unresponsive
The post linked above referenced a point on the board where I2C_SDA could be held low while powering up, but is applicable for a Rev 2 board. Mine is a Rev 3 and the test points near those referenced are not the same.
I had to go to the EEPROM and hold pin 5 low while powering up. Once the front LED starts rapidly flashing then remove the low off pin 5.
This caused the EEPROM from being read and the DFU put the QDX into the state where one can copy the fresh firmware file via the USB to the? QDX file system and the rewritten to the EEPROM.
All is back to normal now.
73,
Kevin K3TL
