Bricked Xiaomi 4a Gigabit and broken bootloader

[aa-nasik]

I have xiaomi 4a with openwrt and breed installed as bootloader. At some point I try to update the bootloader to the newer version but it looks like I miss some steps and got my xiaomi 4a bricked and broke the bootloader.

I try to connect via urt usb ttl but I have no clue:

Can someone provide me the SPI flash memory dump please, I planned to recover using ch341a prog tools.

Thanks in advance

[frollic]

Sure it's not just an incorrect serial port speed?

[aa-nasik]

I don't know what exactly the port speed should be. I tried 115200, 9600, 57600 and still get the weird looking code as above. I doubt the uart usb ttl will works since the bootloader is broken, isn't it?

[ulpian]

Hi,
Check this out.

R4AG&R4A_spi-flsh_dumps

source: Xiaomi Mi Router 4A Gigabit Edition (R4AG/R4A Gigabit) -- fully supported and flashable with OpenWRTInvasion

ulpian

[mk24]

Also check your ground connection. The bootloader is running if it is printing to the serial port. It's on your side that it becomes garbled.

[aa-nasik]

@ulpian

Hi,
Check this out.
http://www.mediafire.com/file/ueyz7zd7q6ys1ex/R4AG%2526R4A_spi-flsh_dumps.zip/file

source: Xiaomi Mi Router 4A Gigabit Edition (R4AG/R4A Gigabit) -- fully supported and flashable with OpenWRTInvasion

ulpian

Thank you very much.

[aa-nasik]

@mk24

Also check your ground connection. The bootloader is running if it is printing to the serial port. It's on your side that it becomes garbled.

hmm, probably the connection is loose