820-3209: Not seeing battery

Anyone have any suggestion. Have a MacBook Air 13 820-3209 that's not seeing the battery. I've tried a known good battery from another unit with the same result.

Only issue i'm seeing so far is the SMBUS_BATT_SCL which reads about 2.84v (3.4v on a good logic board) while SMBUS_BATT_SDA reads about 3.4v.

Ive replace U7000 and checked R5281 (which reads 3.4v on pin 1 and 2.84 on pin 2). The only thing i haven't done is pulled the smc. Just wanted to make sure there wasn't anything else i need to check or could be the issue.

And yes, there was corrosion on the board, which i ran through ultrasonic clean (took images of all corrosion before cleaning).
 

2informaticos

Administrator
Staff member
Compare resistance to ground (diode mode) on SCL/SDA lines.
I bet you have lower value on SCL:
There is not allowed more than 1% difference; usually less than 0.5%.
D6950 is not stuffed, so ISL6259 and SMC suspect.
But clean first battery connector J6950.
You may need to remove it, or even replace.
Leave SMC as last option...
 
Both SCL/SDA have resistance measurement of 0.46Mohms and diode measurement of 0.569(SCL)/0.565(SDA).
Will be pulling the battery connector soon. Would you happen to know where i could find these particular type of connector. I had search in the past but could never find them.
 

JohnB8812

New member
Pull from a donor board. Use heat from the bottom to remove it 450 celsius 120 airflow the other side of the board under the connector to get it to come off without melting the plastic.
 
So it looks like the issue may be due to the corrosion cause I noticed when I press on the board slightly, SCL is back to 3.4v.
Looks like the corrosion runs deep between the layers.
 
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