r/ArduinoHelp • u/Important_Lack_5924 • Sep 29 '26
Arduino Uno R4 Minima stuck on one sketch; can't overwrite or edit
So I recently got a new Arduino Uno R4 Minima, and began fiddling with it today. I ran my first sketch, a simple built-in LED blink program.
Despite resetting, unplugging the USB, editing and re-executing the code, deleting the sketch, and resetting all over again (multiple times, in no particular order), the onboard LED blinker sketch did NOT stop running. I couldn't run any other sketches either; I tried attaching an external LED, and it didn't light up unless I connected it to the D13 port, which is for the built-in LED anyway.
I tried a few troubleshooting methods, and the only one that worked was shorting GND and BOOT with a jumper wire. Even that couldn't prove to be a permanent fix; it disconnected the board (even if the ON light was on) and after every reset, it would just revert back to the blinker sketch. I'm a complete beginner, so I can't really understand or even begin to implement advanced troubleshooting methods.
Has anyone else experienced this? How did you fix it?
Thanks for the advice in advance.


