820-01521 water damaged does not start

2informaticos

Administrator
Staff member
Check R8450-53.
Post voltage and diode mode to ground at SCL/SDA lines.
Should be good to test with known good LCD assembly; backlight adjust comes from it, through I2C bus.
 
You were right, my next step was to desolder the screen on the matrix tapes, it turned out that there are traces of flooding under the screens and corrosion after cleaning everything, the backlight of the screen has returned but there is a new problem, the battery is not charging :-(
 
I'm not sure what you mean but when I see the login screen I also see a battery icon that shows 45% of the battery charge
 
after connecting the charger, the meter shows 19.5 V and 0.3A but I do not hear the sound of USB connection.
There is a sound when the macbook starts up.
 

2informaticos

Administrator
Staff member
Do PRAM reset first.
If percentage appears, battery is recognized.
You should check if macOS says to replace it.
 
PRAM reset did not help

You should check if macOS says to replace it.
I do not have a password to log into the system

Can I restart this laptop and log in the new user without knowing the password to the old one ?

two days ago I'm sure the charger gave 1.5A at 19.5V
Did I damage something?
 

2informaticos

Administrator
Staff member
Be sure battery is properly connected (data and power cable), then monitor PPBUS_G3H voltage.
It should slowly increase, if battery is charging.

Does it start from battery alone?
 
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