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820-00840 20V 0A, PPBUS_G3H 0V

A

ajdoc

Member
MacBook had liquid damage on keyboard/trackpad.
Cant find any liquid on board.

Voltage and diode mode readings on both CD3215 LDOs are correct.

PPBUS_G3H got 0V and 0.000V in diode mode.

F7000 removed and:
F7000/1 13.01V and 0.513V in diode mode
F7000/2 4Ohm resistance to ground, 0.002V in diode mode

Any idea?
 
2informaticos

2informaticos

Administrator
Staff member
Compare short value from PPBUS_G3H with all big coils.
Pay atention to CPU coils; 4 ohm can be good value there.
Any chip from CPU power supplies can transfer that value to PPBUS_G3H, if burnt.
 
2informaticos

2informaticos

Administrator
Staff member
Lift one pin of L7410/20/30, one by one.
When the short disappears from PPBUS_G3H, remove the corresponding burnt U7410/20/30 chip.
 
A

ajdoc

Member
PPBUS_G3H got now 13V.

Without battery it take 0.435A from a charger.
Short fan spin, no chime, trackpad is clicking, caps lock led is not working,
 
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