Bricked Dafang

[Hypfer]

After following the instructions here:
https://github.com/anmaped/openfang/blob/master/doc/WYZECP1/wyzecp1_instructions.md

including the sha256sum verification of the uboot image, my newly bought dafang appears to be completely dead.

No LEDs, no Wifi AP and no other signs of life.

It does take 0.35 to 0.38A but that's all there is.
SKU is ZRM4040RT and according to the label, the manufacturing date is 20200805

For the image, I've used
https://github.com/anmaped/openfang/releases/tag/rc05_01

What can I do now? Am I missing something? Is the guide outdated?

[Hypfer]

Disassembling the device and attaching something to the UART didn't result in anything useful either.
The motors did get very hot. Unplugging them caused the power draw to drop 0.00A

This thing is completely dead. It's just gone.
While this thing is indeed a very cheap camera, I'm very unhappy about this

[Hypfer]

As it turns out, I did in fact not follow the instructions completely.

flash_eraseall /dev/mtd0 was not executed before flashing
always erase mtd0 device before flashing; otherwise you may break your device.

You may want to change that to "otherwise you will break your device"

Edit:

Another thing that could prevent situations like these would be to add a short explaination why fully erasing the flash is necessary.
If anything, that sentence would dedicate a larger chunk of text to this very unusual instruction, which would hopefully prevent the reader from skipping it entirely.

[Hypfer]

I was able to get the camera into a working state again by following this Dafang-Hacks/spiflasher#1 (comment) comment guide here.

For future reference:

/dev/mtd0 is not a regular sane block device like one would expect it to be but is instead raw(?) NAND flash with unexpected behaviour for people who have never dealt with it before.

Apparently it has to be treated differently.