Hi I tried your ideas and double clicked the reset button. But it didn't work. Furthermore I don't have access to a COM port.If the board is damaged, is there a way to check/verify this?
after the double reset you have the com port for 10 seconds, to upload a working sketch
No I don't have the com port. I wanted to upload an empty sketch to override the fault sketch with your method. But after double resetting the IDE didn't offer a COM port for 10 seconds. Uploading the sketch without choosing a COM port during the 10 seconds also fails.
try to start the upload and then the double reset.
When you say you dont have a COM port are you using windows 10 ?If so some versions of windows 10 HIDE the COM ports and you need to re-enable the display in device manager using the SHOW HIDDEN DEVICES.