I re-uploaded a sketch while the serial monitor was printing output.
My Mac shutdown immediately. Now every time I open a sketch and try to open the serial monitor the Mac shuts down.
What happened? Is it fixable or do I have to replace my Arduino Uno.
First REMOVE any items you may have connected to the Arduino including external power.
Make sure it is on a NON CONDUCTIVE surface.
Try another USB lead (They can go bad at the drop of a hat)
Restart the MAc and try again with a simple sketch from the EXAMPLES such as BLINK.
If all goes well your issue was not the Arduino.
THIS POST will also help you get the best out of the forums.
Bob.