820-01958 draws 5v not coming up

[Soji]

The board is very clean no corrosion.
PPBUS_G3H=12.26v pulsing to 11.16v
PP3V3_G3H= 3.3v pulsing to 2.8v.
The rest power rails not present, and no voltages on big coils around u7800.

 

[2informaticos]

Check diode mode an all coils around U7800.
If nothing strange, do the same for big coils on the MLB.

Check U7800 (SYM 1 OF 4) LDO voltages.