Arduino Uno R4 Wifi is not responding

Development Tools Uploading
1

I'm new to arduino, doing some experiente.
But suddenly it's not working.
Some red light is on and the green light is on and bright (not blinking). I'm trying to reset the device.
Followed instruction of this page: https://support.arduino.cc/hc/en-us/articles/16379769332892-Restore-the-USB-connectivity-firmware-on-UNO-R4-WiFi-with-espflash

But still cannot upload sketch to the board.
Here is the error msg,

No device found on COM3
Failed uploading: uploading error: exit status 1

Double pressing the reset button also dosen't work.
With the same usb cable I've uploaded some simple codes to the board. But now it's freeze.
Any help is highly appreciated.

Thanks

2

Hi! This can happen, especially with the Arduino Uno R4 WiFi, which is a bit more "sensitive" than older Uno boards.

From what you describe (solid red LED + solid green LED, unable to upload on COM3), it sounds like your board might be in a "soft-bricked" state.

Here are a few things you can try:

  1. Check the COM Port
    In the Arduino IDE ➔ Tools ➔ Port: make sure the correct COM port is selected.
    If no port appears, try unplugging and replugging the USB cable, or using a different USB port on your computer.

  2. Try a Different USB Cable
    Even if the current cable worked before, some USB cables don't handle data and power well at the same time.
    If you have another high-quality USB cable, give it a try.

  3. Force the Board into Bootloader Mode
    If double-pressing RESET doesn’t work:

  • Press and hold the RESET button.
  • While holding RESET, connect the USB cable to the PC.
  • After 2–3 seconds, release the RESET button.
  • A new COM port should appear (different from before, maybe named "Arduino Bootloader").
  1. Reflash the USB Firmware
    If you haven't completed the recovery process yet, carefully redo the instructions you linked (using espflash), and make sure to:
  • Select the correct COM port.
  • Run the Arduino IDE as administrator (on Windows).
  • Temporarily disable antivirus/firewall if needed (sometimes they block the connection).
  1. Check the Drivers
    On Windows, open "Device Manager" ➔ look under "Ports (COM & LPT)" or "Universal Serial Bus devices".
    If you see a device with a yellow exclamation mark, you may need to reinstall the Arduino drivers.

If none of this works, it might be necessary to do a "forced flash" of the ESP32-S3 chip manually using a tool like esptool.py, but I recommend trying the steps above first.

Let me know how it goes! :+1: