I’m experiencing the exact same blink code on my mystery box AMD 7640U mainboard. In my case I don’t have a full laptop to install it in, making it all the more odd that I get the same blink sequence, while I’m trying to boot it with only the display (also from the mystery box) and a 140W USB C power supply. So that means that while the NO_BATTERY error yours reports is a valid report for me, the fact that mine reports that the touchpad and audio board are present is incorrect. Also although the CPU fan is present on my system, it does not observably spin up. I’ll report back here if I make any progress in debugging this issue.
@pkunk thanks for the suggestion to look at the EC output, I hadn’t read about that before, but that sounds like a great approach for getting some debug info, I’ll give it a try! from what I can find, this article seems like a good starting point at documentation on that process, though I’d welcome any additional suggestions if there’s any other details I should know before connecting to the EC output.