I believed it is not the firmware the issue here why the problem happened. It is the instruction given on that page that will lead to the problem. I also fall to the same problem, no more light on the LED. Searching this forum, I know three have experienced a problem and two have no light on LED. It is not a firmware issue, it is an instruction issue on that page where people follow only to find out later it was the wrong direction. Is there another way to flash uboot image at this current situation?
Maybe something like how to flash/write the uboot image to the router the first time (assuming there is no uboot image yet or uboot image was overwritten with a wrong image) is what is needed here. Is there such a guide to that here? How it was done in factory? We needed that instruction to solve this issue.