A1398 820-3332-A no green light / no power

Hi I have an A1398 820-3332-A with liquid damage, that does not have a green light, but has fan spin (always at full rpm), and consumes about 1.2A in PSU.

I get this values:

PPBUS_G3H = 18.5v
PP3V42_G3H = 3.4v
PP5V_S5 = 5v
PP3V3_S4 = 3.3v
PP1V8_S0 = 1.8v
PP1V5R1V35_S3 = 1.3v
PP3V3_S0GPU = 3.3v
PP1V05_S0 = 1.06V

Can you help?
Last edited:
Replaced Q7030 and C7025.
PPBUS_G3H = 12.25V

U6900 :
1 = 3.4
4 = 3.4
5 = 4.4

1 = 3.2
2 = 3.2
4 = 3.4
5 = 3.4

Still no green light and full fan spin


Staff member
"PPBUS_G3H = 12.25V"
There is a communication problem on battery bus.
Post diode mode and voltage at SCL/SDA lines.

Check for USB activity.


Staff member
"I have USB activity"
I hope you've properly checked for activity, not just USB power.
Do you get image (maybe external) now?
Check continuity from U6900 to central pin of Magsafe connector in DCIN board.
Actually I only plugged in an USB pen and saw the flashing led (assumed that it has activity, and recognized the pen, but not sure). How should i check it in the future?
Now i already have image, and a greenlight on the charger (only with the original charger, not with the PSU), but the fans are at full rpm. How can i check if it is a sensor?


Staff member
Run corresponding EFI ASD.
Or run HWMonitor into macOS at least.

Test known good working trackpad flex/board.
Also test disconnecting webcam.