The owner of this Macbook air tried to install Windows on this machine. During his work the macbook crashed, he tried to restart, but didn't come on anymore.
3,425V G3Hot was just 2,7V. Two bad resistors in the G3Hot supply: R7095 & R7096. After that 3,42V; but no charger LED etc.
PPBUSG3H is 8,1V, so this proofs no communication between SMC and "battery charger" U7100.
What I checked:
PP1V2_S5_SMC_VDDC: 1,2V
SMC_ONOFF_L: 3,3V
SMC_RESET_L:3,3V
SMC_ONOFF_L:3,3V
SMC_BC_ACOK: 3,3V
SMBUS_SMC_5_G3_SDA: no signal measured with scope.
No liquid damage etc.
The only thing I can imagine is a short rise up of G3Hot. Because one of the defective resistors had a bad contact in it. Because they're used to control the G3Hot power chip, I'm afraid of a temporary too high G3hot. Not sure, it could be.
Does somebody has another clue as changing the SMC chip? (hard to find )
tnx
Gert
3,425V G3Hot was just 2,7V. Two bad resistors in the G3Hot supply: R7095 & R7096. After that 3,42V; but no charger LED etc.
PPBUSG3H is 8,1V, so this proofs no communication between SMC and "battery charger" U7100.
What I checked:
PP1V2_S5_SMC_VDDC: 1,2V
SMC_ONOFF_L: 3,3V
SMC_RESET_L:3,3V
SMC_ONOFF_L:3,3V
SMC_BC_ACOK: 3,3V
SMBUS_SMC_5_G3_SDA: no signal measured with scope.
No liquid damage etc.
The only thing I can imagine is a short rise up of G3Hot. Because one of the defective resistors had a bad contact in it. Because they're used to control the G3Hot power chip, I'm afraid of a temporary too high G3hot. Not sure, it could be.
Does somebody has another clue as changing the SMC chip? (hard to find )
tnx
Gert
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