BG96 with no firmware

Hello, This is my first Topic on the forum.

I’m a freelancer and trying to help my client. We have developed a program using a esp32 and the BG96 (using the Dev board).

Code Worked well and a third party was hired to develop the schematics from a PCB, the third party did (as far as I could tell) a good job.

At first, when the new PCB board was delivered we were only able to make the Windows to recognize the board (using the USB_VBUS and all the USB related pins) shortly after a reset, and the COMM port was a “uploader” port instead of the usual AT command ports.

we rapidly understood the USB_BOOT pin was being powerd thru a resistor.

After removing said resistor, now the board is not responsive at all.

My first impression is : “The board don’t have a firmware in it.”

I cant find an official link to the BG96’s firmware and I’m starting to doubt Quectel would ship a BG96 module with not firmware inside.

So, in this topic, I’m actually seeking two answers:

  • “Instructions and a reliable link to download the firmware”
  • There is any possibility of a module to be shipped with no firmware? is this really a thing? if not, is something I’m missing here?

I already went thru all the documentations searching something that would justify why the COMM port is not showing up on the computer. Any help is appreciated.

  1. in general , all the module has been burned with default fw .
  2. based on your descirption , your module enter forcedownload mode ,( SBL mode), pls do not conect USB——boot pin ,

i attache BG96 HW design doc for your reference.

HI Stephen, Thank you for the qucik response, yes this was the previous result.

We then proceed to remove the connection with the USB–boot pin, and now simply no COMM port appears.

Once again ty for your efforts on helping me debugging what is wrong.

I think I can safely assume this is not a problem with the USB Data bus, because I was able to spot the QDLoader before removing the usb–boot pin.

There is any other details I should pay attention or be aware of in this situation?

Thank you and sorry, english is not my first language (But I know you can already tell by now).

pls check the VDD-ext pin and status pin , if the two pin have output normally , it means that ,

you module is running , and then you can check USB part , if not pls check the power part .

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