The daughter board looks like this:

and the back looks like this, input for 12V power from the motherboard and Vret to make 3.3V

Then, because I was reckless, I swapped M2 cards while the PC was powered, thinking they were hot swappable like Sata, but they sure are not. Eventually I caused a partial failure of the board. Gemini helped me debug the linux errors from the cards plugged in itand confirmed my guess that the voltage regulator on the board was now partially damaged and gave power, but not enough to be reliable under load.
A new daughterboard is only $20, but that's 2 week shipping from China while my new server would be down. So, it actually knew the daughterboard, it knew where to buy it from and the shipping delay, and it also knew how it was made before I gave it my picture. It confirmed that the best course of action would be to desolder the 100 component that was an inductor, and I could just unsolder it and connect a new 3.3V source to it.

After helping me find a new 5A Vreg on amazon, it looked at the picture of the board, and it confirmed the top pad, is the one feeding 3.3V to the rest of the board. It suggested I use flux to help unsolder the SMD component after I declined the suggestion to use a hot air gun that would be too likely to remove other components, some of which had to be useful:

yes, it looked ugly, but the inductor was removed safely, I then cleaned the flux

Then I happened to have the right female connector in my collection of cables and plugs (happy it does come handy at least a few times), and soldered in the new Vreg:

I had to move it on the other side so it would fit with the case closed

And there you go, I literally fixed the daughterboard and the PC works again! Yeah! I honestly was impressed by Gemini's knowledge of existing boards and its ability to read pictures I sent it, identify the components and confirm test points and how to verify I was adding the new power source in the correct place.

Back to work!