820-3115 with liquid damage around SMC and SMC_reset. Replaced SMC and it now turns on but powers off about halfway though booting into OS and does not show a green light. Will not turn off if just sitting in boot menu or ASD EFI. Possible Bad SMC?
Go check out why there is no green light, thats probably the only clue you can do something with at the moment.
When I have a motherboard with multiple issues and I can't resolve one, I move onto the other. Often these are related in a way and I end up resolving both.
Does it never have a charging light or does the light dim after the system powers off? From your post I think always?
What's the voltage of SMC_ONOFF_L and other SMC RESET signals? Often when weird SMC related issues occur this voltage is slightly dropping to somewhere between 2.3 and 2.9V. Also keep an eye on PPBUS_G3H with a fast response multimeter, see if it drops
that should be at 3.4v all the time. Bad U5010, bad keyboard, leaky C5710, corroded R5070, or bad SMC. green light isn't on because it thinks you are holding the power button down so it is booting in SMC bypass mode. Good luck hunting!
This board is going to make me go insane lol. Replaced U5010 and SMC_ONOFF_L is back to 3.4V but booting into SMC bypass. Replaced SMC again with nothing changed, C5710 and R5070 looked fine but replaced anyways and still nothing. Is it possible my great donor board SMCS are all dead.