I have been using my Arduino Uno R3 board for a few years now without any issues. However, recently I used the HC-05 bluetooth module with the board, and I'm not sure if this contributed to the problem but the board is no longer being recognized by my Mac. The green LED constantly light is on, but The L LED flashes an orange light briefly when the board is first connected to my laptop but then stays off. Does this mean my board is fried and can no longer be used?
The L led being off while the board is plugged in doesn't mean anything. That LED is connected to pin 13 so it's going to be on or off according to the state of pin 13. A sketch could make it be on or off or blinking at any speed.
If the L LED blinks after you press the reset button, that means the bootloader on the Uno's microcontroller is running.
Does the problem still occur if you disconnect the Bluetooth module from your Uno?
Make sure the USB cable is fully inserted into the the Uno and the computer.
You may have a defective or charge-only USB cable. Try another USB cable.
Thank you for your response! Yes, I tried disconnecting everything and just connecting the board to the computer, and the board is still not being recognized. I will try a new cable. Just out of curiosity, if the USB cable was working fine until now, what would cause it to become defective?
An internal wire in the cable might have broken. The contacts in one of the connectors might have worn out.
Ensure nothing else is connected to the board while you are testing for a viable computer connection.
Some devices you attach may also interfere with USB communications.