MacBook A1990

[iFix]

Hi.

I have this A1990 with the battery not being recognized properly.

SMBUS_3V3_BATT_SCL is 1.2v, and all others are fine around Q6950. I also have PP1V8_SLPS2R. I replaced Q6950 and U6950 to make sure nothing was going on there, and I resoldered the battery board connector to make sure all was good.

Any ideas, please?

Thanks

 

[2informaticos]

Test removing D6950.

 

[iFix]

D6950 doesn't exist on the schematics

 

[2informaticos]

Sorry, I was looking at wrong schematic.
I usually have 10-20 files opened in Acrobat Reader.

Look at U6950 instead...

 

[iFix]

I thought so U6920 it's the protection diode , which I replaced, but I can remove it and try. I'll revert soon

 

[iFix]

After removing U6920 still the same not reading the battery and when I unplug the adapter , the laptop stays on and works.

Battery info about capacity and Cycle count are 0

 

[iFix]

In battery health, it shows service recommended and shows fully charged, and I tried 2 new batteries. The old one was inflated.

 

[2informaticos]

Post voltage and diode mode for SMBUS_3V3_BATT_SCL/SDA lines.
Do the same for I2C_PWR_SCL/SDA.

 

[iFix]

Here they are:

SMBUS_3V3_BATT_SDA - 3.34v
SMBUS_3V3_BATT_SCL - 1.2v
I2C_PWR_SCL - 1.63v
I2C_PWR_SDA - 1.8v

 

[2informaticos]

Looks to have a problem on SCL line.
Diode mode readings?

 

[iFix]

Diode mode readings:

I2C_PWR_SDA - 208
I2C_PWR_SCL - 208
SMBUS_3V3_BATT_SDA - 208
SMBUS_3V3_BATT_SDA - 208

When I measure any point the multimeter makes a clicking sound repeating every second The measurements are without U6902 for both voltages and Diode mode

 

[2informaticos]

I hope you've checked diode mode disconnecting charger and battery data cable.

 

[iFix]

I2C_PWR_SDA - 420
I2C_PWR_SCL - 420
SMBUS_3V3_BATT_SDA - 830
SMBUS_3V3_BATT_SCL - 860
PP3V3_G3H_RTC_X - 347

Not sure how I got those measurements but the data cable was unplugged, only the big screw was on the battery for the power line, so that might have been it . Here are the correct ones

 

[2informaticos]

"
SMBUS_3V3_BATT_SCL - 1.2v
I2C_PWR_SCL - 1.63v"
Are these readings valid w/ and w/o battery connected (including its data cable)?

 

[iFix]

SMBUS_3V3_BATT_SCL - 1.2v
I2C_PWR_SCL - 1.63v"

Yes with data cable connected, and when disconnected I get 3.3v on both places

 

[2informaticos]

Check the markings on the bottom face of the data cable.
Be sure to connect each terminal on its correct side.

 

[iFix]

There's only one way to connect it, with the contacts pointing down, right?

 

[iFix]

The last comment was a joke. I must be very tired not to notice that I've plugged in the cable the other way around. That solved the battery reading, now jus to solder back U6950 cause it's showing service , maybe it's even gone bad the battery

 

[iFix]

Thank you so much 2informaticos, for the help on this one, I appreciate it

 

[iFix]

Hi Another question about this one... Now the battery is reading and charging, I also installed a new os but it still shows service battery. All components are back in place. I tried multiple batteries and also different flex cables for the batteries. Any suggestions?