MacBook Pro A2289 TouchBar (820-01987-A) - No power / No image - Previous Liquid damage

[ronaldo]

Hello, community!
I need help, please.
I have a MacBook Pro A2289 TouchBar that initially had liquid damage on both sides of the board around U3200/U3100.
I've reflowed the area and then cleaned on U.S cleaning.


Currently, the motherboard (820-01987) partially supports the 20V load.
The 2 charge ports are in 0.5A unstable, and are close to 10W but always drop down to approximately 1W unstable.

The trackpad reacts to the click.
Tried DFU mode and it doesn't enter in DFU mode.

Testing the voltages I'm wondering if you could help me find where the problem is coming from?

_________________________________________________________
L7030 : 12,60V

L7690 : 3,3V
L7670 : 5,12V

L8410: 0V (backlight coil)

L8100 : 1,2V PP1V2_S3
L8102 : 0,959V PPVCCIO_S0_CPU

L7702 : 0V PPVCCEDRAM_S0_CPU
L7270 : 1,021V PPVCCSA_S0_CPU

L7210 : 0,81V PPVCC_S0_CPU
L7220 : 0,81V PPVCC_S0_CPU

L7410 : 0V PPVCCGT_S0_CPU
L7420 : 0V PPVCCGT_S0_CPU

________________________________________________________

PP3V3_S5 - 3.3v present for 10 secs and then 0v
PP1V8_S5 - 1.8v present for 10 secs and then 0v
PPVPCORE_S5 - 1.06v present for 10 secs and then 0v
PP1V_PRIM (PCH POWER) - 1.06v present for 10 secs and then 0v

PP1V8_S3 - 0
PP1V2_S3 - 1.20v present for 10 secs and then 0v
PP1V_S3 - 1v present for 10 secs and then 0v
________________________________________________________

PP1v8_AWAKE: 1.8v
PPVDDCPU_AWAKE: 0.54v
PPVDDCPUSRAM_AWAKE: 0.8v
PP3V3_AWAKE: 3.3v
PP1V2_AWAKE: 1.2

PP1V8_SLPS2R: 1.8
PP1V1_SLPS2R: 1.1v
__________________________________________________________
Do you have a solution?
thank you in advance for your help

 

[2informaticos]

You've mentioned some voltages drop after 10s; drop, or cycle back to normal value?
Check if all SLPS2R and AWAKE voltages are steady on that time.
Do you note any drop 12.6V-12.3V on PPBUS_G3H?

 

[ronaldo]

The drop voltages goes to 0v and stay at 0v.
All SLPS2R and AWAKE stays steady On.
PPBUS_G3H - always at 12.6V.
Nothing abnormal under thermal camera.

 

[2informaticos]

" L8100 : 1,2V PP1V2_S3
---------------------
PP1V2_S3 - 1.20v present for 10 secs and then 0v"
So not sure which voltages drop.

What about L7210/20?
Measure all of them after 10s...

 

[ronaldo]

L8100: 1,2V PP1V2_S3 - as soon as the charger is plugged the voltage goes to 1.2v and after about 10 secs it drops to 0v and stays at 0.
L7210/20: 0.8V and same as above it drops to 0v after about 10 secs.
I've done a short video with the issue and the thermal hot spots while turning it on.

 

[2informaticos]

So the voltages on these colis also drop; you didn't mention that before.
We need to know which (if) voltages are stable.

Be sure all voltages mentioned as stable don't drop after the 10s.
If AWAKE and SLPS2R voltages are stable, machine should appear on DFU.
Follow all the steps from DFU tutorial.
You can use SE032 pads to force it into DFU mode.

 

[ronaldo]

Ok, I will try to use the SE032 to enter in DFU mode.
How can I use these pads to enter in DFU mode?
Is it by shorting PP1V8_SLPS2R and SOC_FORCE_DFU and does it needs a keyboard, charger, or battery connected?
I've tried this and still nothing.
Thanks

 

[ronaldo]

Sorry, I miss a lot of information in my first post.

On PPBUS_G3H - drop from 12.6V to 12.3V then return to 12.6V

All were measured for 10 secs.

L7030: intermittent voltage starts with 12.59V then vary to 11V and drops to 3.50V
L7690: PP3V3_G3H - 3.3V stable
L7670: PP5V_G3S - 5,12V drop to 4.7V and back to 5.12V
L8410: PPVIN_S0SW_LCDBKLT - 0V

L8100: PP1V2_S3 - 1.20v present for 10 secs and then 0v

L8102: PPVCCIO_S0_CPU 0,95V - present for 10 secs and then 0v

L7702: PPVCCEDRAM_S0_CPU - 0V not present
L7270: PPVCCSA__CPU_R - 1,021V present for 10 secs and then 0v

L7210: PPVCC_CPU_PH1 - 0,81V present for 10 secs and then 0v
L7220: PPVCC_CPU_PH2 - 0,81V present for 10 secs and then 0v

L7410: PPVCCGT_S0_CPU - 0V not present
L7420: PPVCCGT_S0_CPU - 0V not present
_________________________________________________________________

PP1v8_AWAKE: 1.8v drop to 0V after 10 secs and back to 1.8V
PPVDDCPU_AWAKE: intermittent 0.9V, 0.73V, 0.54V, 0.9V and back to 0.54 steady.
PPVDDCPUSRAM_AWAKE: intermittent 0.8V, 1.06v then back to 0.8V steady
PP3V3_AWAKE: 3.3V drop to 0V after 10 secs and back to 3.3V
PP1V2_AWAKE: 1.2V drop to 0V after 10 secs and back to 1.2V

PP1V8_SLPS2R: 1.8V drop to 0V after 10 secs and back to 1.8V
PP1V1_SLPS2R: 1.10v drop to 0V after 10 secs and back to 1.10V

 

[2informaticos]

So machine is in some kind of power cycle.
No DFU possible, if AWAKE and SLPS2R voltages are not stable.

Remove and reball U3100/200.
Check if any resistor, or capacitor is corroded on USB-C area.

 

[ronaldo]

I'm scratching my head now.
Both U3100/200 were replaced and the same is happening.
The USB-C area looks fine.

 

[2informaticos]

Something else was affected by liquid spill.
Maybe not in USB-C area, if now get 20V on input.

Looks like problem appears when CPU tries to boot.