820-01814 5v 0.260A and PP5V_G3S 0v

[thomamagic]

hello,
i have mainboard 820-01814 stuck at 5V / 0.260A - The history is that the machine broke following a slight fall

PPBUS_G3H 12.28 V Main power rail, present and stable
PP5V_G3S 0 V 5 V rail not generated by the board
PP3V3_G3H_T 3.3 V Standby 3.3 V rail, OK
PP1V8_S5 0 V Not present
PP1V1_SLPDDR 1.09 V OK
PP0V9_SLPDDR 0.9 V OK
No shorts detected on PP3V3_G3H or PP1V8_SLPS2R
Injection of 5 V / 0.5 A on PP5V_G3S: fans spin immediately, even without battery or USB-C connected
U7800 replacement: no effect, PP5V_G3S remains at 0 V
U8110 replacement: no effect, PP5V_G3S remains at 0 V

 

[2informaticos]

Why did you inject voltage there?
Did you check its enable first?

If a power rail is not enabled, you will find 0V.
1V8/3V3/5V_G3S are all in G3S state.
Did you search only for 5V_G3S?

G3S is controlled by T2; its power on sequence breaks for some reason.

I suspect broken traces, or solders under some BGA chips.
Dropped machine diagnostic is a nightmare usually...