820-3437-B not turning when battery is pluged

[farfan14]

hi everyone, this is my first post and first macbook repair try. normally i am doing iphone repairs. so i tried to start doing repair with your help. thanks in advance for everyone.

so i have in hand A1466 820-3437-b it was water damaged. first i detected that there was backlight problem and i changed backlight ic and now backlight working without any problem. but have another problem.when i am plugging charger without battery connected macbook turning on and working but with battery connected not turning on and doesn't have any light on charger,

p.s i also detected that even without battery also not turning on always but most of times its turning on* ( in 10 tries about 8 times is turning on 2 times not). and also a bit strange is that without battery when i am plugging charger no any sense and no any light about 1 minute and after that green than orange light comes up and mac is turning on.

i have changed u7100, u7501 and u8080. also tried another battery. nothing changed. thanks in advance again

 

[farfan14]

please give me an advice from where should i start checking a fault

 

[dukefawks]

PPBUS voltage? Inspected IO board and flat cable for corrosion? Orange light must always be present on charger even without battery.

 

[farfan14]

PPBUS voltage? Inspected IO board and flat cable for corrosion? Orange light must always be present on charger even without battery.

orange light is present after 1-2 minute of plugging charger and after orange light it starts turning on. but with battery even orange light not present

 

[farfan14]

first i checked in condition when it is without battery and already orange light and turned on.

1) PPBUS_G3H 8.58V
2) PPBUS_G3H_R 8.58V
3) PPBUS_S5_HS_COMPUTING_ISNS 8.58V
4) PPBUS_S5_S_OTHER_ISNS 8.58V

now will check again without battery but when isn't orange light yet (sometimes when plugged charger imediatelly turning on and have orane light but most of times it starts after 1-2 minutes after pluggeing battery) so now i will check during this 1-2 minutes period. and after that with battery when never have any light and no fan

it is correct process of voltage checking in this situation ?

 

[farfan14]

now i checked with battery connected and PPBUS_G3H is 6.93v and pp3v42_g3h is 3.389v

on the battery connector
1) PPVBATT_G3H_CONN have 6.93v
2) SMBUS_SMC_5_G3_SCL have 3.425v
3) SMBUS_SMC_5_G3_SDA have 3.382v
4) SYS_DETECT_L have 0.225v

 

[farfan14]

and also i catched maybe somethinfg interesting.

first time when plugging charger (without battery connected) green and than orange light comes imediatelly as it should be and mac is turning on without any problem and during this PPBUS_G3H is 8.58v and than if i remove charger board still have voltage saved about 2volts and droping slowing down. during this process ( while dropping voltage from 2volts to 1 volts) if i plug charger nothing happenes no any light but as soon as voltage drops at 1volts light comes up on charger and mac is booting.

so after unplug charger if i plug again charger imediatelly nothing happenes until voltage on PPBUS_G3H droppes to 1volt.i am monitoring this process with multimeter and as soon as voltge dropes to 1 volt light comes up and booting.no matter after unplug charger you will plug again or not plug voltage is always there remained and dropping slowly from 2volts to 0 volts if not plugged again.if plugged as soon as dropped to 1 volts loght comes up. i tried this process about 10 times and i always same. voltage dropping process takes about 1 minute. but with battery connected no any light but PPBUS_G3H is stable 6.93v

 

[Inwerp]

I might sound stupid but is it a proven good battery?
check all the current sense shit on the battery charger, feedback and boost around power and charging mosfets. Read charger chip datasheet and check if your voltages are meeting charging conditions. (Be extremely careful with probes, it is pretty easy to blow up the board here). If you have it in stock, replace charger chip and mosfets, just to be sure you're not fiddling with a bad chip

 

[farfan14]

I might sound stupid but is it a proven good battery?
check all the current sense shit on the battery charger, feedback and boost around power and charging mosfets. Read charger chip datasheet and check if your voltages are meeting charging conditions. (Be extremely careful with probes, it is pretty easy to blow up the board here). If you have it in stock, replace charger chip and mosfets, just to be sure you're not fiddling with a bad chip

sorry for late response i wasn't working at weekends thats why i couldn't do farther testing. thanks all of you for trying me to help

yes battery is tested working.about your advice please be more clearly because of as i said in my first post i am begginer in this job. anyway many thanks

 

[farfan14]

please advice me what should i do next.thanks

 

[farfan14]

so i am stuck here.i hope someone can help me out.thanks

 

[JohnB8812]

Where was original corrosion? This sounds like a bad battery to me...inspect for corrosion near SMC or under the battery connector. Does this run off of a battery or does the charger have to be plugged in?

 

[farfan14]

Where was original corrosion? This sounds like a bad battery to me...inspect for corrosion near SMC or under the battery connector. Does this run off of a battery or does the charger have to be plugged in?

tried another battery and still same problem. with battery connected no any light on charger and without battery booting mac and there is orange light as well. but if you read my earlier post is start booting and light after ppbus_3gh is under 1 volts and than without battery ppbus_3gh (when booted) is 8.58v and with battery no any light and ppbus_g3h is 6.92v. corrosion was on the half of the motherboard.