820-00165-a PP3V3_S4 Dead After Generic Charger

[managerharry]

MacBook Air, 820-00165-a. Occasionally have green / orange light when good charger is plugged in. Board has no visible signs of liquid damage, but customer did admit to using a generic charger.
PPBUS G3H is 8.64 as measured at F7140.
PP3V3_S5 = 3.32 measured at C5126
PP3V3_S4 is .4 measured at C5460, resistance to ground measures 495

Where to go from here?

 

[2informaticos]

Are these voltages when no Magsafe light present?
If not, post them.

Did you try to start in SMC bypass?
Did you try MLB alone, disconnecting LIO flex, TP, etc?
Do you get 3V_S5?

Post PM_RSMRST_L and PM_PWRBTN_L.
Trigger SMC_ONOFF_L and check reaction (drop pulse) at PM_PWRBTN_L; use R5115/16 pads, instead of power button.

 

[managerharry]

Those measurements are when no magsafe light is present, and with only DC in connected. Does not start in SMC bypass mode.

P3V3S5_EN_R measured at R7552 is 3.44
PM_RSMRST_L = 0
PM_PWRBTN_L = 1.56, when shorting R5115 drops to around .3 or .5 and goes back to 1.56

 

[2informaticos]

"Do you get 3V_S5?
---------
P3V3S5_EN_R measured at R7552 is 3.44"
I didn't ask for enable signal; check L7560 voltage.

Also check 3V3_SUS.

 

[managerharry]

L7560 measures .68.
3V3_SUS = 0
Thank you.

 

[2informaticos]

"L7560 measures .68."
Is that diode mode, or voltage?

Post U7501 voltages...