RAK11720 Fail to enter bootloader

[ebenlouw (Eben)]

I have two modules, each on their own RAK19007 dev board.

I’m flashing the examples to them, one of the boards now doesn’t want to program anymore. Other one is working fine. Using Arduino IDE.

Screenshot below. More Info on problem module :

• Windows detects the Comport
• AT commands not working, no response from module.

Seems like module is dead or not responding anymore.
I’ve tried reflashing the Bootloader by selecting programmer as Ambiq SBL, then burning bootloader…this also doesn’t work.

I have a Segger Jlink available if that can help. How do I test to see that the module is not dead?

[carlrowan]

Hi @ebenlouw ,

Have you tried this video guide to attempt recovery? Of course using Jlink should be possible too.

With regards to know if the module is still ok or not, my simple method to assume that there is chance that it is not dead is if Jlink still recognize it and there is no abnormal current drawn by the board (also not heating up). But of course, this is not assurance.

[ebenlouw (Eben)]

Hello Carlrowan…thanks for the guide.

I followed it, still unable to burn bootloader. Soldered a jumper onto SWO and VDD.

[ebenlouw (Eben)]

Hello, I’ve managed to upload the firmware using Jlink.

Using the Segger JLINK Base and J-Flash Lite…I’ve managed to load the original RUI3 Firmware.