820-3115 no green light

[Yoel Ren]

Hi, this board came in with corrosion around smc and its back
After corrosion is cleaned, realize pp3v42 is shorted to ground.. im using shortkiller by sunshine but only can inject around 3.3v ( no amperage controller ), and then the deadshort’s resistance became around 100 ohm .., how do i detect which component has the leakage ?

 

[2informaticos]

Several times I found this symptom caused by a capacitor.
Inspect under microscope all ceramic caps from 3V42 rail.
Be aware, some of them can be placed after 0 ohm resistor, or small coil; in such case, will not appear directly connected to 3V42_G3H in boardview/schematic.

I recommend you to reball SMC also...