XIAO show only green led

Hello,
I love the XIAO boards for their tiny size but I am facing a reliability issue with this board that I am not going to consider them for future projects (sadly). 2 out of 4 boards are already dead after very short time of use. When I plug the USB I get only the green led lighting and the windows isn’t recognizing my board. It could be that I have shorted my board somehow, so I got another new board, works for few hours then dead!
I have tried to reset and to enter boot mode with shorting the two pins near the USB as described on the official website but this didn’t helped, still only green led.
Is there a known production issue with those boards?

Can you be more specific? We have not received any similar quality problems. What program are you using or what have you done to make XIAO’s unusable?

I don’t know how specific should I describe the issue as there is nothing unusual that I have done with my boards other than uploading some basic Arduino code to show some text on an 1.3" oled display (see below my complete code).
I have found some other people complaining about a similar issue: e.g.

As I said, the first board dying didn’t bother me, thinking I may have (or not!) touched the pins with a metal object laying around and shorted some pins, so I used a second board and then after few hours (another code for using Accelerometer) it happed again with the new board!
Do you have any guide how to test my boards and if they are rescuable? (shorting the reset pins on the board with a tweezer didn’t help as my pc is not recognizing the board at all)

/**************************************************************************
 This is an example for our Monochrome OLEDs based on SSD1306 drivers

 Pick one up today in the adafruit shop!
 ------> http://www.adafruit.com/category/63_98

 This example is for a 128x32 pixel display using I2C to communicate
 3 pins are required to interface (two I2C and one reset).

 Adafruit invests time and resources providing this open
 source code, please support Adafruit and open-source
 hardware by purchasing products from Adafruit!

 Written by Limor Fried/Ladyada for Adafruit Industries,
 with contributions from the open source community.
 BSD license, check license.txt for more information
 All text above, and the splash screen below must be
 included in any redistribution.
 **************************************************************************/


#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "Fonts/FreeMono9pt7b.h"
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3D ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
char message[]="Don'tpygforget about the exam";
   int x, minX;

  void setup(){
  Serial.begin(9600);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.setFont(&FreeMono9pt7b);
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setTextWrap(false);
  x = display.width();
  minX = -27 * strlen(message);  // 12 = 6 pixels/character * text size 2
   display.display();
  }

  void loop(){
       
   display.clearDisplay();

   display.setCursor(x,24);

   display.print(message);

   display.display();
   x=x-2; // scroll speed, make more positive to slow down the scroll
   if(x < minX) x= display.width();

}```

I think it is extremely unlikely that you have corrupted XIAO through contact at the same time, it seems possible that you have chosen the wrong development board model or uploaded the wrong program. Are you using an XIAO BLE?

This might be the case as I am using Arduino IDE Version 2.0.2 which is not recognizing my board sometimes and I have to tell the IDE manually which board and port I am targeting.
Although I am pretty sure that my code was successfully uploaded at the moment when the board went off. Even if I am wrong and I have selected the wrong board, the IDE won’t let me upload the code anyway (as I noticed some times), right? But let’s assume this is the case and I did choose the wrong board and managed to upload the code, now what? Is there anything I can do to rescue my Xiaos?

Are you using the XIAO nRF52840?

No, both boards are the standard version (SAMD21G18 @48 MHz)

Can you open your computer’s device manager? Then check inside to see if the device XIAO SAMD21 is there (it may be inside other devices), if it appears inside other devices, please right click on it and try updating/installing the driver.

By the way, a question, after you shorted the RES pins, did you see the orange beads of XIAO flashing?

I can see Seeeduino XIAO under Universal Serial Bus devices, but it is hidden, and trying to update the driver didn’t help, windows says I have the latest driver.
The orange led is always off, when plugging usb to power the board I get only green led stays on. Nothing changes or flashes when I short RST pins once or twice.

Perhaps the following link may be helpful to you.

Thank you for the link, I will try this method to “rescue” my boards if I have time soon.
But honestly this is indeed production issue, as the bootloader should not be wiped out easily. The steps in the link requires another board and some time to do. Why should this be a customer problem? Shouldn’t the bootloader be write-protected out of the production at the first place?

I totally agree with you. I have asked Seeed why the bootloader is not protected but no answer. On the other hand, Adafruit’s SAMD21 board had a properly protected bootloader.