Macbook A2681 820-02536

Instafixx

Active member

Mar 20, 2025

• #1

Device had no trackpad keyboard and will only boot on charger.
UT360 was shorted. Replaced. KP/TP is now working.

But the device doesn't seem to detect battery and will only work on charger.
Settings show battery not connected and not charging and the MacBook being stuck at 1% perennially.

 

2informaticos

Administrator

Staff member

Mar 20, 2025

• #2

Check SYS_DETECT_L and BMU_CWL_DET_L levels; both must be low.

 

Instafixx

Active member

Mar 20, 2025

• #3

BMU_CWL_DET_L was 0.0002
Not shorted?

SYS_DETECT_L i ll check and get back.

 

2informaticos

Administrator

Staff member

Mar 20, 2025

• #4

I meant voltage level.
If R51B1 is soldered, BMU_CWL_DET_L is grounded.
That's good; just be sure SYS_DETECT_L has also 0V.

 

Instafixx

Active member

Mar 21, 2025

• #5

Without Battery connected checked at J5150. SYS_DETECT_L has 0 Voltage.

 

2informaticos

Administrator

Staff member

Mar 21, 2025

• #6

That should be 0V even with battery.
In fact, is what battery expects to be enabled.
You can force it shortin to ground, just in case.

Now check voltage and diode mode to ground at SCL/SDA lines pf battery bus.

 

Instafixx

Active member

Mar 21, 2025

• #7

It is a battery issue after all