MacBook Air (Retina, 13-inch, 2020) 820-01958-A. Boot loping after liquid damaged

ronaldo

Member
Hi. I need help, please.
This MacBook had liquid damage around C7661(replaced), R5430(resolder), Q7660 and Q7680(All cleaned with flux), small oxidation on C6532.
After cleaning all corrosion and resoldering some components I've cleaned with Ultra Sonic cleaning.
Measuring on L9060 it starts on 12.60V then drops to 12.30 for 3 secs and back to 12.60.
PPVIN_G3H_P3V3G3H starts with 12.61V and drops to 12.30V for a few secs and back to 12.61V.
I've replaced even U7650 and still the same issue.
Can't boot in internet mode or from an external system it keeps rebooting.
Can someone point me in some direction?
Thanks
 

2informaticos

Administrator
Staff member
Any liquid sign on audio card?
Remove it and inspect hidden side; also check audio flex and connectors.

Did you try DFU?
 

ronaldo

Member
Yes, there was liquid on the audio card, I forgot to mention. The audio card had U.S cleaning.
I tried to boot with the audio board disconnected and the same.
DFU mode works and revives option goes all steps fine. But after restarts the same issue.
It keeps restarting after trying to boot.
It's not working on the battery, only with the charger connected.
I've done this video showing the voltage-in.
 

2informaticos

Administrator
Staff member
I bet some T2 data line to audio board was damaged.
Such small audio board receives PPBUS_G3H and leakage to data lines is very often.
 

2informaticos

Administrator
Staff member
We didn't get any positive feedback about changing T2 on the forum.
Did you try DFU restore?
This will erase SSD.
If data is important, check first if can get access to it in Target Disk mode and save data.
 
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