820-4924-A 2015 Retina 13in green light on charger no power on need some help

[calbuh]

ieee I am the lucky one my first apple mb and is a nightmare
THX

 

[calbuh]

PPVCC_S0_CPU i have noticed that i have only 10.6 ohm to ground and, on diode measurement i have 0.0006v, is this normal ?

 

[calbuh]

I have noticed that on cpu_vccsense_n i have 0 volts to the ground ( on diode measurement) and 1.1 ohm to the ground, both c7261 and r0960 are ok is that normal ?
on u7200 i have 12.53 on pin 17 and 0.52 on pin 8(cpuvr_fb2) nothing else

 

[dukefawks]

That is all normal. Power is pulsing so system is trying to boot up but fails. As said this could be 100 different thing. Most likely cases are U6100 and termination resistors/traces, crap under SMC, U1950 pin 8 or damaged/corroded resistor somewhere.
Nothing more really can be done in this case. Maybe upload some high-res pictures for assessment.

 

[calbuh]

Thank_u for your patience.
After looking again and again through microscope seems that the only area with corrosion is r7752 and r7753 (seen in picture)
I also noticed that the only rails that are not jumping is pp5v_so, pp5v_s0_cpuvr, PP5v_S0_vmon ( neither of these have short to ground)

 

[dukefawks]

I still have no other ideas for you. U6100 has more to it than just that picture......