Macbook A2681

[bryceonrice1111]

Macbook A2681
USB meter cycles between reading 19.93v and 0v every 5 seconds.
PPBUS_AON cycles between 0v and 11.9v when plugged in.
Not sure what to check/replace.
Any help appreciated.

[mon2]

What is the history of the unit? Liquid spill?

Using the Apple original and recommended power adapter for this macbook?

Remove all power. Disconnect the battery. Meter in resistance mode. What is the resistance (ohms, not diode mode) to ground of PPBUS_AON @ fuse F5200?

What is the resistance to ground of:

SMBUS_BATT_1V8_SCL
SMBUS_BATT_1V8_SDA

[bryceonrice1111]

Laptop is in great physical condition, no liquid damage or any signs of damage to the board. The owner says the laptop died in the middle of using it.

Yes using the original charger. Same behavior between usb c port and magsafe ( when connected to magsafe blinks orange light on/off every 5 seconds).

Resistance to ground of PPBUS_AON on fuse F5200 reads O.L on the multimeter.

SMBUS_BATT_1V8_SCL reads 127.6k ohms
SMBUS_BATT_1V8_SDA reads 123k ohms

[MobileXT]

Look like your PPBUS_AON is shorted to ground. You need to inject voltage on ppbus I would recommend start with 1volt and look on the cpu if not getting hot. If not getting hot then you adjust the voltage to 5v then 12v.

[mon2]

No. Resistance to ground is OL = over limit so select a higher resistance scale on the meter. Not to be confused with 0 ohms like when the probes are shorted or touching each other.

Be sure to test the resistance to ground on each side of the fuse, in case the fuse is blown. That is rare for the fuse to be blown.

[bryceonrice1111]

TIL how to manually set the range of my multimeter lol.

Its reading 2.9 Megaohms on both sides, I tested the fuse for continuity I believe its fine.

[bryceonrice1111]

mon2 any idea what to check?

[mon2]

Try a DFU.

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