Ive been trying to solve a problem I have with my Arduino Leonardo. The sketch successfully uploads with the RX and LX leds flashing in the correct order and the IDE showing finished uploading, but the sketch wont run. I don't know if this has to do with the boot loader or if the micro controller is completely bricked. For some reason a different sketch that only includes serial communication with my computer works just fine. All it does is prints the state of digital pin 2 on the serial monitor.
Anyway that sketch seems to work, but then I tried the blink sketch and it uploads with the leds flashing but neither the built in led or an external led blinks after uploading or restarting the sketch.
How can we help without seeing your sketch? It may be doing exactly what it is programmed to do but not what you want it to do.
Weedpharma