820-3437-B No Power No Green Light No Orange Light

[MeTech Turkey]

My customer brought me a 820-3437-B and had a coke liquid on it. We have changed the infected parts of the mainboard. But still no power.

And I have checked all big coils on diode mode. Found short on PP3V42 but thats been sorted. But still have voltages written below after short gone. I saw green and orange light once then U5450 burned out. Changed it with another one from donor board. It was okay saw the green and orange light again for a second and again no more. Any ideas where to check?

SMC_RESET_L = 0.V
PPBUS_G3H = 0.7V on R7006
Pp3v42 = 1.6V on L7095
Pp5v_s5 = 0V on C7400
3V3_S5 = 0.6V on C8180
L7130 = Starts with 0.6V and goes down
L7520 = 0V
L7560 = 0V
L7430 = 0V
L7630 = 0V

Thank You

 

[2informaticos]

With such low voltages, did you check diode mode on PPBUS_G3H and 3V42_G3H?

Post U7100 basic voltages; pins 1, 2, 3, 9, 12, 13, 14, 15, 17, 19, 20, 27.
Also check at Q7010.

 

[MeTech Turkey]

PPBUS_G3H = 0.175 on diode mode
3V42_G3H = 0.379 on diode mode
U7100
Pin 1 = 0.003V
Pin 2 = 16.70V
Pin 3 = 4.44V
Pin 9 = 0.065V
Pin 12 = 1.62V
Pin 13 = 0.001V
Pin 14 = 1.56V
Pin 15 = 0.60V
Pin 17 = 0.006V on
Pin 19 = 5.06V on
Pin 20 = 5.06V on
Pin 27 = 16.49V on

Q7010 On diode mode
Pin 1 = OL
Pin 4 = 2850 on C 7012
Pin 6 = 2967 on c7012

Q7010 Voltages:

Pin 1 = 16.92V
Pin 4 = 6.85V
Pin 6 = 16.90V

 

[2informaticos]

Check R/D7005.
Post U7090 voltages.

Also check resistance (ohm scale) between pins 17/18 and 27/28 of U7100.

 

[MeTech Turkey]

R7005 ON DIODE OL ON BOTH LEGS
D7005 ON DIODE MODE
PIN 1 = 0.177
PIN 2 = OL
PIN 3 = 0.405

R7005 VOLTAGES
PIN1 = 16.95V
PIN 2 = 2.65V
D7005 VOLTAGES
PIN 1 = 0.520v
PIN 2 = 2.66v
PIN 3= 2.40V

U7090 VOLTAGES
PIN1 = 0.84V
PIN2 = 1.61V
PIN3 = 1.60V and keeps going down while holding
PIN4 =1.60v
PIN5 = GND
PIN6 = 2.40V
PIN7 = 3.40V keeps going down while holding
PIN8 = 2.40V

Resistance Scale Between 17/18 Pins = 3.5 If I did it right. First time Im doing this
Resistance Scale Between 27/28 Pins = 20.5

 

[2informaticos]

"R7005 VOLTAGES
PIN1 = 16.95V
PIN 2 = 2.65V"
Do you still think is good resistor?
I was expexting to get its ohm value in fact.

Check diode mode to ground at C7092 too.

 

[MeTech Turkey]

C7092 ON DIODE MODE = 0.398
I DONT THINK THATS A GOOD RESISTOR WILL TRY TO CHANGE IT.

 

[MeTech Turkey]

After I changed R7005 with a working one now I get green and orange light but what I realised that I get around 7.04V on L7095 pin2 which needs to be 3.42 I think is that normal but also I realised that I have 60watt charger here not 45watt does it makes it happen?

 

[MeTech Turkey]

I have replaced U7090 and 3V42_G3H been sorted too. I am going to check it for the last time

 

[MeTech Turkey]

I have inspected 2 more problem one of them is booting the macos. It takes ages to boot the macos and it shuts itself on login screen after a while. And also it does not recognize battery and charging of course and no keyboard or trackpad working

 

[2informaticos]

This Mac is plenty of problems.

Did PRAM reset?
KB/TP also not working on boot menu ?
Tried known good trackpad flex/board?

Check diode mode to ground and voltage on SCL/SDA lines of battery bus.

 

[MeTech Turkey]

KB /TP are working well did PRAM reset but still booting in ages.

SMBUS_SMC_0_S0_SCL = 0.583 on DIODE Mode
SMBUS_SMC_0_S0_SCL = 0.552 on DIODE Mode
SMBUS_SMC_0_S0_SCL = 2.724 on DIODe Mode

When I put the battery on and plug in the charging cable I get 2.2V on C6950 and C6951 I think the problem is the battery but not for sure.

And what do you think about macbook starst so slow and on login screen after like 20 seconds it shuts itself done. Where can it be happening?
I did PRAM reset and SMC reset

 

[2informaticos]

"SMBUS_SMC_0_S0_SCL = 0.583 on DIODE Mode
SMBUS_SMC_0_S0_SCL = 0.552 on DIODE Mode
SMBUS_SMC_0_S0_SCL = 2.724 on DIODe Mode"
Has this any sense for you?
I asked about SCL and SDA; any reason to post 3 times SCL, with such different readings???

Test with another battery, or check its battery with battery tester.
NLBA is the best tool for this purpose:

One moment, please...

About slow machine, try known good BIOS, clean ME.

 

[MeTech Turkey]

I am so sorry for that confusion mate.

SMBUS_SMC_0_S0_SCL = 0.756
SMBUS_SMC_1_S0_SCL = 0.581
SMBUS_SMC_3_S0_SCL = 0.704
SMBUS_SMC_5_S0_SCL = 0.553
SMBUS_SMC_0_S0_SDA = 0.757
SMBUS_SMC_1_S0_SDA = 0.581
SMBUS_SMC_2_S3_SDA = 0.748
SMBUS_SMC_3_SDA = 0.685
SMBUS_SMC_5_G3_SDA = 0.550

Okay now I was new to the clean ME phrase and searched it on internet. And understood how it works and what it is. But what devices I can use for it. On youtube I found a device called Medusa but I cant find it somewhere selling in Turkey. Is there any other way or device I can use for this without desoldering right from spi socket on mac?
Thank you

 

[2informaticos]

So many SCL/SDA lines go to your battery???
We talk about battery bus here.
I didn't see its SCL there; unless you've named it "S0" by error.
Try to post what we need, without irrelevant checkings; which can only complicate the job.

0.553/0.550 is good enough for diode mode.
Still no idea about their voltage.

CMIzapper Medusa-3

Many other useful tools there...

 

[MeTech Turkey]

D6950
1 SMBUS_SMC_5_G3_SCL = 3.44V
2 SMBUS_SMC_5_G3_SDA =3.44V
I think the battery is the problem
And do you have bios file to do Clean ME we dont have medusa here in Turkey but found another tool but need a clean bios file mate.

 

[2informaticos]

820-3437-Working-CleanME.rar

drive.google.com

 

[MeTech Turkey]

Hello again, my CH341 bios programmer just arrived (as this is the only one I could find.) First I tried it with its latch but unfortunately it is not touching the pins of the U6100 so I tried to took the U6100 off from the board and tried to reprogramme it on the device. But it didnt work again. I have read that some computers need power on but I dont if I need to do it.
But in anyway I dont know if I am doing everything right or am I missing anything else?
Thank you for being patient with me.

Thank you

 

[2informaticos]

Are you getting good contacts for the WSON chip on the CH341 socket?
You can also use classic SOP-8 chip, like MX25L6405 for this board, at least for test.

 

[MeTech Turkey]

I had succeded on reading chip but I realised that you can see on video. The chip must be programmed as 3.3v but when I choose the chip after detect it comes as 1.8V. And you can see what I am doing step by step on video. Am I doing anything wrong or missing? Because after I programme the chip I click on verify but it gives me an error that you can see on attached photo and after I put this chip on board it does not boot (no apple logo or anything. It was booting before but it was slow.) Do I need to do any modification or something to force ch341 to programme the chip as 3.3V?
Video: Video Of Programming
Photo: Verify Error
Thank you