A1989 20V 0amp

[tommy97]

Hi,

I've got A1989 which was liquid damaged, laptop was working however it was extremely slow, I've replaced palmrest and cleaned the board and since then it does not power up. Laptop goes up to 20V boost to 0.30 amps and then goes down to 0 after few seconds.

PPbus 12.58V

While battery connected it goes to up to 2AMP's, if everything connected trackpad does clicking. Connected to 2nd MacBook for DFU however it does not see the device.

[reformatt]

How did you clean the board? Did you use anything abrasive and potentially knock anything off? Where was the palmrest sourced from? Is the Touchbar known to be good? If the trackpad is clicking and PPBUS is 12.6V, then your T2 is functional and booting. Possible you have a missing or shorted power rail further on in the sequence.

Slow machine is usually missing sensor data, and this can even be missing SMBUS lines from the battery due to a bad battery flex cable.

[tommy97]

It was cleaned with IPA, palmrest is fully tested an working from other device, tried to install board in old one and it is the same. I've did visual inspection of the board and all components are on them place.