Man, it's so wild that you posted in this thread again because I was about to. I have the same exact board and very similar issues. I was going to get those voltages you wanted off the board I'm trying to fix and post (they may be different as I have multiple issues).
A rundown, maybe you can compare and find something similar/different:
A friend gives me a (SAE-003) Slim with no power. I first test the board and nothing with the PSU plugged in.
I then test the PSU and it gives 12v and 5v. Ok, so that's fine. Yet, no 5v even at the plug on the board or 3.3v anywhere at all.
After some detective work I find that the RT5069A chip near the Southbridge often goes bad in Slims, it handles the main 5v / 3.3v lines and I find this video that shows a lot of voltages across a different Slim board (but with many common or exact same setups):
The area around RT5069A on my board did not match at all on that diagram. Plus, the board had shorts all over it. So tons of shorts, no 5v and no 3.3v. It only had 2v (still not sure how or what creates the 2v).
So I remove the RT5069A and there is my 5v line. I can now trace 5v across most of the board outside of the 12v line (still not sure how much they mingle, if at all).
I order two new RT5069A PMIC chips and replace it. Still no 3.3v but 5v remains so the chip is good.
Then I find a blown mosfet near the front USB port on the opposite side of the board (you might wanna check that out). Hole blown right in it but removing it changed nothing.
I can't progress as is so I finally have enough of a reason to remove the Southbridge (the blown mosfet leads right to it) and there is my 3.3v line and most of the shorts are gone.
However - and this is where we may be able to help each other - my HMDI IC is shorted like crazy. Almost every pin (if not all) and the filters behind them all short. The port pins all short.
So, I know those often fail and it's not uncommon for a power surge to kill both Southbridge and HMDI IC so I remove HDMI IC.
The filters now no longer short but the insane thing is that the chip itself shows NO READINGS off the board. I've never seen a chip so damaged that it doesn't even register continuity across ground or anything. I mean not a single pin reacts to any measurement, be it diode, ohms, continuity, etc. It's bad-bad.
I'm now down to whether or not the APU is shot before I even try to order new chips for the board because I know of no known-good values for a few caps still showing as shorts somewhat near the APU. Many inductors that look like caps around the APU (under even) show as short even on good boards.
So, if you can, how about I upload an area I could have you test for me and I'll do the same for you? I'll even upload some basic diode readings for the HDMI chip and the RT5069A if those can help you.
Thanks for any time you took reading this and possibly helping.