820-4924 liquid damage ISL no PPBUS

[Ryanlen2]

Board came in with major liquid damage on ISL and surrounding components. Replaced ISL and repaired all damaged traces the best that I can.

https://photos.app.goo.gl/eeELDEhBkWtdzGS6A


1.520V on PPBUS / .134 Diode Mode

1.520 at pin 1 of L7130

16.69V on DCIN

16.69V on Pins 1,2,3 of Q7130

3.9V ACIN on ISL

17/18 of isl 4ohm

27/28 of isl 20 ohm

pin 21 of isl - 0v

pin 23 of isl1.525V

pin 24 of isl - 1.526V

I have replaced - Q7130


Any help would be awesome. Thanks.

 

[2informaticos]

C7125 is there and good?
Be sure to have continuity from Gs/Q7130 to U7100.

Resistance to ground on L7130?
Post more voltages for U7100; 10, 11, 12, 13, 14, 9, 15, 19, 20.
Do you have magsafe light?

 

[Ryanlen2]

Green/orange Light on charger.

Good continuity between u7100 and Q7130 is good.


0.911K resistance on L7130

pin 10 - 3.30V - 3.419V (Jumps)
pin 11 - 3.301V - 3.423V (Jumps)
pin 12 - 2.66V
pin 13 - 3.218V
pin 14 - 3.118V
pin 15 - .061V
pin 19 - 5.45V
pin 20 - 5.46V

C7125 is present. Not sure how to check if it is good so I swapped it.

Thanks!

Sometimes green light flickers for a little while before going to amber.

 

[2informaticos]

"pin 12 - 2.66V"
It comes directly from 3V42...

 

[Ryanlen2]

I should have saw that...

Ran wire from r7112 to pin 12 and c7012 and still only 1.5v on PPBUS.

 

[2informaticos]

Do you have correct voltage at pin12 now?
Post pins 1, 9, 26 voltage too.
I bet you still have some traces/resistors affected there...

 

[Ryanlen2]

Pin 12 is 3.427V

Pin 1 - 0.003V
Pin 9 - 4.265V
Pin 26 - 0.018

it was pretty beat up. Your most likely right.

 

[2informaticos]

"Pin 9 - 4.265V"
There is your problem.
Check again resistance between pins 27/28; directly on the chip!

 

[Ryanlen2]

Sorry for the delayed response have been closed for a while here from the holiday. You were right! Thank you very much! There was a pinhole in TP between pin 27 and pin 2 of C7120. Sorry for the wild goose chase man, I honestly couldn't see it and my joints on the isl looked strong, so I assumed I had good connectivity. Didn't mean to waste your time, because I do appreciate it. So, I do have ppbuss back but still not turning on. I don't trust this battery so I ordered a couple new ones. Will post back, have a good one.

 

[2informaticos]

Do you get correct PPBUS_G3H now (aprox 12.5V)?
The board should start without battery, just plug in the magsafe.