820-01987 dead

[BlueGold]

Hey i have a Problem with a Macbook A2289.

Suddenly dead no water dmg, board looks like new.

No Voltage at PP3V3_G3H_RTC.

I replaced U3100 but changed nothing.

What i need to do next, any ideas?

 

[2informaticos]

First of all, welcome to the forum!

Any reason to change U3100?
Can we know actual PPBUS_G3H voltage?

 

[BlueGold]

Thank you very much,

Well i thought it was the IC, cause i have no output voltages there.
And i am a beginner in MacBook repairs. I do more Smartphone Logicboard repairs.

PPBUS_G3H = 0V

 

[2informaticos]

It is the first voltage you need to get.
Check diode mode to ground there.
If good, post U7000 basic voltages; P_IN, AUX_DET, VDDA/P, SMC_RST_IN, A/BMON.

 

[BlueGold]

I did from beginning, no short there.


P_IN = 5V
AUX_DET= 1,3 V
VDDA/P= 5V
SMC_RST_IN=0V
A/BMON= 0V

 

[2informaticos]

Also post PPBUS_G3H with battery connected.
You probably need to change U7000...

 

[BlueGold]

Same 0V

My first though was also to change U7000. But somewhere i read that i need PP3V3_G3H_RTC to get PPBUS_G3H, thats why i tried to get this.

totally wrong. I will change U7000 and write results in a few days.

Thank you so far

 

[2informaticos]

T2 boards have different power on sequence than old boards.
3V3_G3H_RTC comes from PPBUS_G3H...

 

[BlueGold]

Hey i change the U7000. And after that i found that PPBUS_G3H is shorted. ... silly me...

now i have 0.220V on PPBUS_G3H...

Some ideas now ? the short is fixxed now.

 

[2informaticos]

Which component was shorted to ground?

 

[BlueGold]

It was the cap C6556

 

[2informaticos]

Did you check F7000, is still good?

 

[BlueGold]

The fuse is oke.
When i connect the charger it takes some time to go on 0,230 V. it goes step by step.

Maybe the new u7000 have some problems ? what did you think ?

 

[2informaticos]

Post again U7000 mentioned voltages.
Maybe the new chip is bad, or not properly soldered.

 

[BlueGold]

P_IN = 5,2 V
AUX_DET= 1,3 V
VDDA/P= 5V
SMC_RST_IN=0V
A/BMON= 0V

 

[2informaticos]

U7000 MUST generate PPBUS_G3H without any control from T2; even with just 5V from USB-C input.
Compare diode mode to ground at pin 2/F7000 with good board.

Consider to change Q7030/40 and check R/C7030/40.

 

[BlueGold]

I changed U7000, I have PPBUS-G3H back

but no boot anyways.

P_IN = 5,2 V
AUX_DET= 1,3 V
VDDA/P= 5V
SMC_RST_IN=0V
A/BMON= 0V

these are the same

 

[2informaticos]

No need to repeat these measurments, once you've got PPBUS_G3H.
It is back, but what exact voltage???

Do you get 3V3_G3H_RTC now?

 

[BlueGold]

PPBUS_G3H 12V

I have 3V3_G3H_RTC back too.

 

[2informaticos]

Please, post more atention when you read.
I asked about EXACT voltage.
12.3V and 12.6V is not the same; is what I expected to know.
I'm very sure you don't get 12.0V...