Hi everyone, dealing with this 'fiddly' board here. No sign of corrosion anywhere. Board on bench with no battery.
First inspection - shorted PP3V42_G3H which was strange - 3V voltage injection initially took no amperage, after a few tries though the short was gone. Now I am getting a stable PP3V42_G3H of 3.42V.
I have all PPBUS_G3H / PPBUS_S5's however they are only 8.15V.
PP3V3_S5_AVREF_SMC is there,
SMC_BC_ACOK, SMC_RESET_L are high
PM_BATLOW_L is low
some activity on SMBUS_SMC_5_G3_SCL/SDA & SYS_ONEWIRE (singular spikes).
bias voltage around 1V on SMC_XTAL_R & SMC_XTAL (my tiny oscilloscope doesn't capture anything - but it did not capture anything on another board either).
At this point I can't get to S5 state - no SMC_PM_G2_EN means no S5_PWR_EN and no PP3V3_S5 and no PP5V_S5- as there is no SMC_PM_G2_EN for U7501 to start it off.
I replaced U7501 thinking it pulls down SMC_PM_G2_EN, no joy.
Reflowed SMC, no joy either.
Original Magsafe - LED stays off. It turned orange once (?!).
Anything else to try please?
First inspection - shorted PP3V42_G3H which was strange - 3V voltage injection initially took no amperage, after a few tries though the short was gone. Now I am getting a stable PP3V42_G3H of 3.42V.
I have all PPBUS_G3H / PPBUS_S5's however they are only 8.15V.
PP3V3_S5_AVREF_SMC is there,
SMC_BC_ACOK, SMC_RESET_L are high
PM_BATLOW_L is low
some activity on SMBUS_SMC_5_G3_SCL/SDA & SYS_ONEWIRE (singular spikes).
bias voltage around 1V on SMC_XTAL_R & SMC_XTAL (my tiny oscilloscope doesn't capture anything - but it did not capture anything on another board either).
At this point I can't get to S5 state - no SMC_PM_G2_EN means no S5_PWR_EN and no PP3V3_S5 and no PP5V_S5- as there is no SMC_PM_G2_EN for U7501 to start it off.
I replaced U7501 thinking it pulls down SMC_PM_G2_EN, no joy.
Reflowed SMC, no joy either.
Original Magsafe - LED stays off. It turned orange once (?!).
Anything else to try please?
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