Uploading the program results on no output over the TX1.
And you know that how?
Am missing something?
Yep. The TX light is NOT controlled by the Mega. It is controlled by the USB to Serial chip. With nothing connected to the USB side of the chip, nothing gets sent, so the TX light doesn't blink. It doesn't matter that the Arduino is sending War And Peace to the USB-to-serial converter.
Post a schematic AND a photo of your actual setup.