Flashing bootloader and firmware after MCU replacement

[Ancharas]

Hello!

My MCU died a heroic death after short circuit to 5 V. I replaced it to the same model (STM32F446ZET6). I flashed bootloader as desribed here: https://github.com/bigtreetech/BIGTREETECH-OCTOPUS-V1.0/tree/master/Firmware/DFU%20Update%20bootloader

After this I used my SD card (2 GB, FAT32) to flash firmware. But the file firmware.bin didn't rename to firmware.cur, and my PC didn't define my Octopus board as COM-port.

Later I found a complete image with bootloader and firmware here: https://github.com/GadgetAngel/BTT_SKR_13_14_14T_SD-DFU-Bootloader/tree/main/bootloader_bin/backed_up_original_bootloaders/Octopus%20V1.1/Bootloader_and_Firmware

After flashing the same way my board was defined as COM-port, and started answer to Gcode commands. E.g., answer to M115:

>>> M115
SENDING:M115
FIRMWARE_NAME:Marlin bugfix-2.0.x (May 13 2021 14:16:08) SOURCE_CODE_URL:github.com/MarlinFirmware/Marlin PROTOCOL_VERSION:1.0 MACHINE_TYPE:OCTOPUS_V1_0 EXTRUDER_COUNT:4 UUID:cede2a2f-41a2-4748-9b12-c55c62f367ff
...

But I still have no possibility to flash firmware via SD card. I checked wiring to MCU and short circuits between MCU pins - it's OK. Also I can see a blue indicator flashes up when I insert SD card. I used anothes SD card with no result.

Here is M20 answer:

>>> M20
SENDING:M20
echo:No media

I saw the Status indicator is blinking after power up on some videos, but it shines constantly on my board.

So I have two questions:

1. How can I fix bootloader?
2. How can I flash firmware without SD card?

[Ancharas]

The problem was solved after re-soldering. Also there is an alternative solution. Details are in my Reddit thread: https://www.reddit.com/r/BIGTREETECH/comments/11ulbkk/octopus_11_flashing_bootloader_and_firmware_after/