I confirm that, without flash chip (or with a flash chip wrong programmed), LED do not light up on the board. In other words, the LED off not means a damaged board
After some trial with SPI programmer, I reached this - poor -goal:
Boot and Recovery Environment for Embedded Devices
Copyright (C) 2020 HackPascal hackpascal@gmail.com
Build date 2020-01-14 [git-b25d507]
Version 1.1 (r1280)Bootloader data is corrupted!
System halted.
I made many trials: with/without powered usb hub (when I connect the clamp, power consumption rise to 300 - 400 mA), with usb3 and with usb2 (tha seems works better), changing type of CH341A programmer, etc.
Maybe others are more skilled or mure luck than me, but I guess that if the flash chip remain mounted on board, the writing will be an hard thing (my opinion, not tested: during writing, CPU "turn alive" and interfere with writing process). Maybe, if we can found a bridge or a resistor or a reset line that shut off the cpu, this can help.
Instead, writing with CH341A on a desoldered chip is relatively easy and reliable.
Wait a moment. I read all threads you write. 5 min pls
What version you use for BREED? I setup installation only for stock u-boot.
Bootloader report is corrupted.
You have mtd0 backup?
@minax007
Files in https://www.lanzoux.com/b01hjjtzg aren't dump of the original flash chip, but Padavan firmware 
I'm looking for a dump of Xiaomi 3C model (and also for the Xiaomi 3A model), with partition layout or description, if possible. In particular, I would like extract a copy of U-Boot bootloader (not armored, but, at least, with UART enabled)
@eduardo010174
Can you help me?
I used breed-mt7628-hiwifi-hc5661a, that worked fine in the past. I used this because the flash chip now is soldered and Breed file is smaller than U-Boot (the time during I can write is short). Then, probably, I will migrate to U-Boot
It is corrupt only for writing problems.
It was to highlight to @earth08 that a board that appears dead can also revive
uuuu. I have on u-boot.bin in my stock files.
I upload for drive and send to you.
https://drive.google.com/drive/folders/15hqyFojSkOiH5MCjrmWBwCO1h3ZAPtaS?usp=sharing
You have UART and SPI programmer?
Many thanks. You confirm me that is setted as UART enabled?
Do you have a copy of "Factory" partition? I promise you that I use only to compare with my mtd0 dump, to understand where is positionned in the file.
Yes, I have UART and SPI programmer, but I'm tired to desolder and resolder those little chip 
I'm very confused. For use image with U-boot with UART enable is more needed only patch on bootloader sector.
If you only need a full stock image with UART enable, I have this image.
I use clip for reading and writing on flash.
Mee too. But I realized that aren't reliable. With chip desoldered, I tried with many routers, changing software and SPI programmer, and writing and reading report me every time same result (files matching).
But with chip soldered, instead.... I writed and a readed (with same hardware configuration) and file don't match. Never.
Wait, this image is builded for my on my router. Not have on internet. I use only for local tests. I uploaded now for same link above. I finish to upload to cloud this image.
Humm chip is not ok or your flasher not working.
Thanks. The file that you provided me is "UART enabled"
I'm sure that chip and programmer are OK. On many forum, many people reports that the programming with chip soldered is very problematic.
I use on Linux Mint with flashrom and not have problems.
List all steps you use for flash.
What wonderful thing, if also will be true for me 
I will try.
Which kind/model of SPI programmer do you use?
I use this kit
https://pt.aliexpress.com/item/4001045543107.html?spm=a2g0o.order_list.0.0.3867caa4kl0WKI&gatewayAdapt=glo2bra
I tried in 72730218 ways!
Connecting clamp before and after inserting programmer in the USB port, with/without powered USB hub, differents type of programmer, differents type of software: every time, no good news.
The chip is correct detected by programmer? On flashrom is possible test before read/write actions.