So, I disassembled the USB CAT cable GX12 connector and found the wires tightly twisted together right where the wires were soldered to the connector pins.? I carefully untwisted the wires and made sure there were no shorts, then carefully inserted the black connector piece into the TX-500.? Started the update process again and found that there was now a COM7 option, which worked!
I now have the latest 1.05.00 installed.
This whole process took more time than I ever anticipated.? I am just glad that there was nothing wrong inside the radio.