820-00164-a Liquid damage Boots but no green light no charging

[drewrox2009]

I have a liquid damaged 820-00164-a board here
computer boots, does not charge battery.
no green/orange light

was not booting, cleaned up r7005 area where there was corrosion, also corrosion near f7140
f7140 showing .3ohms may be hardware resolution

ppdcin_g3h_chgr 14.8v
ppdcin no short to ground
isl6259 area untouched by liquid
ppvbat_g3h_chgr_r Stable at 8.6
chgr_bgate not stable stable at 8.6 for about a second then falls off and takes about 10 seconds to bee stable for another moment

am i looking at a dead isl?
or am i possibly gettting bad info to the isl making chgr_bgate jumping up and down?

 

[dukefawks]

If there is no green light I would first inspect/replace IO board and cable.

 

[drewrox2009]

I was afraid of that, this is one of the io boards, i do not have, but i have one on order. will post back if i have any further issues after that gets in.

 

[dukefawks]

You can check if ACOK is present from ISL6259

 

[larossmann]

if you want to cheat you can do the following.

1) study what MAX9940 & TC7SZ08FEAPE look like on ANY unibody board from 2010-present or any retina board besides 12" macbook.
2) look at your DC in board and identify these two.
3) run PP3V42_G3H, SMC_BC_ACOK, and SYS_ONEWIRE via jumper wires from the mainboard to the DC in board.

Don't do this as a final fix, but it is a way of testing if it works. The airs use the same onewire circuit as the unibodies and retinas do, the chips are interchangeable, the pinouts are the same.

 

[drewrox2009]

Louis! That is a great Cheat! I will have to try it next time, I did get lucky and it was just corrosion on ppbus_g3hot and a bad i/o board. Now i need to order another one to keep one for testing purposes.