820-3536-a - Dead pp5vS4/0

[Siekrut]

Hi,

I am new to this i need some help


First question PP5vS4 has a resitance to ground of 18 ohms when i plug in the power, when unplugged it keep dropping from server 100s Kohms

these are my voltages,

ppbus_g3H 12.6v
ppbus_S5_hs_computing 12v6
ppbus_s5_hs_other5v 12v6
ppbus_s5_hs_other3v3 12v6

ppdcin_g3H_iosl 16v6
PPDcin_g3h 16v6

pp3v42_g3H 3v4

ppvrtc_g3h 3v3

PP5v_s5 5v
pp5v_s4 0v
pp5v_s0 0v

pp3v3_s5 3v3
pp3v3_s4 0v4
pp3v3_sus 3v3
pp3v3_s3 0v3
pp3v3_s0 1v7

pp1v35_s3 0v
pp1v5_s0 0v

 

[Siekrut]

I noticed pp5vs4 has a resitance to ground of 18ohm but only when powered, is this normal ?

 

[JohnB8812]

You can't measure resistance to ground when the board is powered on..... Any history liquid damage drop etc?

 

[Siekrut]

no liquid damage but i found a bit of green stuff above u7700 at R7752 and R7753 but that should not stop te macbook from booting

 

[dukefawks]

There is corrosion so probably there is more. The usual suspects apply, U1900, U1950, J6100, U6100 area including all the termination resistors to U6100, crap under SMC.