I've come across a broken laptop before that had a complex power control computer like what you've described. I ended up repairing it by hard-resetting the NVR

I've come across a broken laptop before that had a complex power control computer like what you've described. I ended up repairing it by hard-resetting the NVRAM and forcing the power control computer back to its initial "reset" state. This was a common enough problem that the manufacturer had a step-by-step guide showing how to fix it on their website. The moral of the story is that adding complexity, even when that complexity is designed to increase robustness, usually just means that there are more systems that can fail.