Macbook A1706 820-00239 Amp Meter Reboot

[Instafixx]

Hello,
So this macbook came with one port rebooting the amp meter.
One port stuck at 5V and other were normal at 20V.

Checked the board.
Corrosion at U3100 and the corresponding charging port.

Replaced the charging port so now all 4 ports drawing 20V.

How to confirm whether U3100 need to be replaced?

 

[2informaticos]

The machine works now?

U3100 may be good, if its port switches to 20V, without battery connected.

 

[Instafixx]

No the machine doesnt turn on. I get the mouse click for sometime when connected to power

 

[2informaticos]

Does it charge the battery?
Which voltages do you get on the MLB?
Any reaction pressing power button?

Use 61/87W charger for tests.
Try SMC bypass, just in case.

 

[Instafixx]

So without a battery it turns on. But when i connect the battery its not doing anything. Not charging the battery.

I am uing 96W charger.

Should i just leave it on charge for a few hours and see if the battery picks up charge or do we need to replace the battery.

 

[2informaticos]

You should test with known good battery.
Or check the battery with a dedicated tool, like NLBA1.

 

[Instafixx]

Tried a known good battery. Works now. Thanks

 

[Instafixx]

Have another case. Same Model .
Works off a charger but not when connected the battery. Tried a SMC Bypass as well.

 

[2informaticos]

Tested with good battery?

 

[Instafixx]

Yes

 

[2informaticos]

Works with both charger and battery connected?
Or just with charger alone?

 

[Instafixx]

Works only with charger

 

[2informaticos]

Any history available?

Check ohm resistance over C7020/23.
What is PPBUS_G3H voltage with both charger and battery connected?

 

[Instafixx]

PPBUS_G3H with both charger and battery is 12.6V

C7023 is .503
C7020 is.405

 

[2informaticos]

I meant resistance between capacitor pins, not to ground.
You should get 2 ohm aprox.

 

[Instafixx]

i am getting .013 in diode mode between pin 1 and pin 2 of C7023/0

 

[2informaticos]

I said to check resistance (ohm scale).
R7020 + R7021 + R7022 -> 2 ohm aprox over C7023.
Same applies for C7020.

Check mentioned resistors for correct values (1 ohm).

 

[Instafixx]

C7023 and C7020 is 2.5 ohms.

R7021/2 is 1.3 Ohms

 

[2informaticos]

Check battery SCL/SDA lines voltage; w/ and w/o battery.

 

[Instafixx]

We have a problem now. I put the board back on and plugged in the charger to check the voltages and suddenly the machine wont turn on now and only the right fan will spin at max continuously and then will stop.

PPBUS_G3H is at 13V

After a few tries it turned on without the battery. But still only 1 fan is spinning at max.
But its turning on like before only off the charger.

INSTALLED ANOTHER WORKING BOARD ON THE CHASIS. BOTH FAN SPIN AND THE BATTERY WORKS TOO. PROBLEM FROM THE CUSTOMER'S BOARD ONLY.