Dear Arduino users,
We have recently received reports about Arduino UNO WIFI Rev2 that was shipped out without bootloader. If you believe you are in this situation please contact Technical Support: support(at)arduino.cc and provide the following information:
- Batch number: This is a number printed on a white label sticker on one side of the box.
- Photo of the Arduino board from either side and photo of the box showing the batch number.
- Invoice
If you are not sure whether your board has bootloader loaded or not, you can check this by powering the board (USB to your PC) and press the RESET button. The built-in L LED should blink twice quickly. If it doesn't, there may not be a bootloader on your board.
Also, before reporting a new issue, make sure that the core 'Arduino megaAVR Boards' is installed in Arduino IDE. This can be done from Arduino IDE menu Tools > Board > Boards Manager: search for 'Arduino megaAVR Boards' > Install/Update. Then try to upload a sketch and do the RESET test in order to make sure.
Thank!