no boot 820-3435

[Mr.J]

Hi guys,

i've got an 820-3435 11" MBA that occasionally boots up, and most of the time decided not to boot up.
Here are the readings i've taken while it's playing up. When its not booting, i do get a green to orange led light from the charger, but no fan spin. Since i can't get it into s4 s3 state, i'm guessing there's nothing on pm_slp_s4_l so i went and checked, there's nothing on both pm_slp_s5_l and pm_slp_s4_l. Now i'm confused that normally the PCH should be dead but since it does sometime boots up, I must be missing something. Where else should i be looking at or did i do something wrong?

ppbus_g3h 8.52V
ppdcin_g3h 15.3V
pp3v42_g3h 3.36V
ppvrtc_g3h 3.27V

pp5v_s5 4.97v
pp5v_s4rs3 0v

pp3v3_s5 3.28v
pp3v3_s4 0.30v
pp3v3_sus 3.28v
pp3v3_s3 fluctuating between 2V and 0.15V
pp3v3_s0 fluctuating between 1.43V and 0.19v


pm_slp_s5_l 0V
pm_slp_s4_l 0v


corrosion found
u5810 c5812 c5813
u3210 pin 5 - s4_pwn_en


Edit:

The board was not liquid damaged, however I did found corrosion around U3210 and U5810.

 

[dukefawks]

Corrosion on pin 5 of U3210 could cause no power. Remove U3210 and clean it up. Board should power without it, jus no thunderbolt. Also check J6100 and U6100 area for corrosion. Pin 8 on U1950 is also infamous for corrosion.