AirGradient Forum

Need Help Recovering AirGradient V9 After Firmware Flash — No Serial Port, No LEDs, No Display

I’m having trouble getting my AirGradient One working again after attempting to flash it with newer firmware. Initially, I could flash once, but the device never booted after that. Now, when I connect it via USB, it does not show up as a serial port device in the Chrome serial device list, nor am I seeing it being recognized by the OS. Additionally, no LEDs or display show any signs of life.

Here is what I have already tried:

  • Holding down the BOOT button while plugging in to enter bootloader mode (no visible feedback, but expected)
    
  • Using the original cable and USB port, as well as different combinations on multiple computers
    
  • Checking for serial ports manually on different OSes (MacOS and Linux)
    
  • Attempting to flash again via the browser flasher and esptool, but the serial device never appears
    
  • Confirmed the PM2.5 sensor’s fan spins up when powering, so the board is receiving some power
    
  • Ensured the USB cable is a data cable
    

I have a USB-UART adapter I’ve used for flashing things before, so if connecting that and attempting to re-flash is an option, I’d just need to know where I should hook up to.

Additionally, I have a few ESP32-C3-Mini and a hotair rework station, so if its possibly the ESP32 thats the problem, I can give a shot at swapping it out… though I purchased the mini’s by accident, and haven’t actually used the hotair machine on SMB components just yet.

Thanks in advance for your help!

I was playing with new firmware on my outdoor monitor and got myself into a boot loop situation when trying to install firmware using some other tools. Each time I was able to get it back by doing the first option you mentioned of holding the button on the back of the device while plugging in the USB cable. I certainly had some situations where a known good cable wouldn’t make a connection but after seating and reseating the cable multiple times it just started working.

So I don’t have much to offer other than suggesting to do it again, making sure to hold the button the entire time while plugging in and keep holding the button.

This is the firmware you are trying to flash now to get it back to a known good configuration?

You can always use the Support page and click on “Contact Us” to send a message directly to support who might have additional methods to try:
https://www.airgradient.com/support/