So I had a nano I was working with, having no issues. I started to compile and upload a sketch, and I wanted to plot the serial output so I opened the plotter. As far as I can tell, this disrupted the programming of the nano and now all it does is flash the LED very quickly. It does not respond over USB at all now. Did I really kill this board? Is there any way to fix it?
It would not "KILL" the board but doing what you did could have corrupted the bootloader.
You failed to mention which IDE, OS etc etc etc. There is a post near the top of the forum I would suggest you read it.
Alright, I fixed it with the reset button. I was having a hard time finding the right query as I am still pretty new to this world.
The solution was to hold the reset button on the unpowered arduino, apply power, start program upload in the Arduino IDE, wait for the 'Uploading..." text to appear above the console, and release the reset button.
That sometimes works too