Ender 3 S1 STM32F401 Bootloader Erased – How to Restore?

[ronniedex]

Hello,
I accidentally erased the bootloader on my Ender 3 S1 STM32F401 motherboard, and now I am unable to flash any firmware. The board is still detected via USB, but I cannot connect to it (e.g., with Klipper or other tools).

I have a Raspberry Pi Zero 2W, and I was wondering if I could use it to restore the bootloader. If so, how can I do it?

Additionally, I am having trouble identifying the BOOT0 pin on the motherboard. Can anyone help me locate it?

Thanks in advance! 🚀🔥

[mriscoc]

Check: https://github.com/search?q=repo%3Amriscoc%2FEnder3V2S1+bootloader&type=discussions