820-00165 Working without power board only

[PJs]

I cannot figure out this one and I've got a feeling that this is just some stupid mistake I'm doing over and over again

No liquid damage, oxidation, signs of previous repairs or any other damage anywhere in this laptop, system board looks almost like a new one. Customer says it just did not turn on one day.

MagSafe light works - green then orange, but it does not turn on as the PM_SLP_S4_L is always low (0.01V). But if I disconnect the "data ribbon" (J9500), then it suddenly starts working and turns on. I tried 2 other known working power boards and ribbon cables, no luck with that (I also tried the original power board+ribbon in a different machine and it also works). I inspected the whole board, especially the SMC and J9500 area from all angles, everything looks OK there. I also did not find any shorts on J9500.

Thank you

 

[2informaticos]

Post basic voltages and signals when LIO flex is connected.
Be sure none of J9500 pins moves and no corrosion present.

 

[PJs]

PPDCIN_G3H 16.65V
PP3V42_G3H 3.43V
PPBUS_G3H 8.58V
PPVRTC_G3H 3.32V

PP5V_S5 5.01V
PP5V_S4_IPD 5.01V
PP5V_S3 0.00V
PP5V_S0 0.00V

PP3V3_SUS 3.32V
PP3V3_S5 3.32V
PP3V3_S4 0.00V (not shorted)
PP3V3_S3 0.00V
PP3V3_S0 0.00V


PP1V8_S3 0.00V
PP1V5_S0 0.00V
PP1V2_S3 0.00V
PP1V05_SUS 1.06V
PP1V05_S0 0.00V

All the voltages are stable.

J9500 is super clean, no bent or even discoloured pins, no moving pins (all of them soldered well), no stains or oxidation, it looks really perfect, I inspected it under microscope from all sides, not just from the top.

Thank you

 

[2informaticos]

Are you using original Apple Magsafe 2 charger?
Don't use 1-->2 adapter.

Trigger SMC_ONOFF_L and check for any reaction at PM_PWRBTN_L; supposing 3V3_SUS is present.
Post SMC_ADAPTER_EN, PM_BATLOW_L, S5_PWRGD, PM_DSW_PWRGD, PCH_DSWVRMEN.