TX output does not stop flashing

Hello.
I connected a module to the TX0 digital output of my arduino MEGA board, ran the program, and then deleted it. When connecting the board to the computer, the TX led turns on and I can't turn it off because when I start the serial monitor it only picks up the output of that module even though it doesn't connect and it doesn't let me carry out other projects.
Thanks

Please consider changing the language used in the title of this topic

Please provide details.

  1. Which module?
  2. What does "deleted it" mean? Did you upload e.g. a blank sketch?
  3. Did you disconnect the module?

An Arduino Mega has 4 UARTS; why did you choose the first one?

Like deleted by uploading a blank/empty sketch? Or did you get creative and drop to the command line and use avrdude or similar 'hidden' utility?