COM-Port problem

Hey there,

I am new here and have no experience with Arduinos and Teensys.

What´s the problem: I have written this little Sketch, which should just return "Hello World" at the serial monitor and uploaded it to my Teensy 3.6. But it said me: "No serial port, please select with Tools > Port" So I went to Tools, but couldn´t select Port. Then I went to the device manager. There I have seen that my Teensy is connected to the PC, but no COMs. I`m sure that my Teensy is working, because before I wrote this sketch, I uploaded a sketch to let a led blink and it worked.


void setup() { Serial.begin(38400); } void loop() { Serial.println("Hello World"); delay(1000); }

Hardware: Teensy 3.6 Arduino IDE 1.8.5 Windows 10

It would be nice, if someone could help me :) Thank you

Your code looks fine.

Many times I have had problems with com ports. They appear and disappear at random to me sometimes.

  1. Unplug and plug back in and check if the com port shows up
  2. Use a different port
  3. Use a different cable
  4. Is the board being powered by the USB? Do the lights come on? You mention you were able to compile and upload previously.
  5. Is the arduino program being compiled as a Teensy, or is it set up on something like the Mega? I have had this switch sometimes if I close the program and open up arduino again.
  6. If all that fails, you could maybe create a virtual port. This is time consuming and annoying, but might help if nothing else does.


Thank you for your reply.

I have tried all these steps till point 5. I also thought of creating a virtual port, but I thought there might be an other way to solve the problem.

Restart the computer? Or find a different comp and try that one? It seems to me that it just needs to be reset, then it might display the com port.

This is the point. My computer can´t find even one com