Macbook Air A1466 does not turn on when pluged

[delphi_firebird]

Hello

I have a Macbook Air (820-3437) that have an startup issues :

- it starts right away when i plug the charger ( even with a good connected battery) .
- when shut down, if i press the power button it wont startup when the charger is plugged in but starts when i unplug the charger ( on battery ).
- i have no issue with charging battery .
- i had already checked SMC_ONOFF_L , PM_PWRBTN_L are OK

Can you please help me to figure out the problem ?
Thank you

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

Are you using the official power adapter ?

Remove all power.

Disconnect the trackpad cable to the logic board.

Connect the external magsafe power adapter.

Does the logic board start up on its own ?

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

Thank you for the fast answer .

yes, i am using the original adapter .

I have already removed the motherboard ( there is no trackpad )

yes the logic board start up on its own when power adapter is plugged in ( and battery is disconnected ) witch is a normal behavior .

Then, i can shut down the logic board by shorting ( long ) SMC_ONOFF_L on R5115.

But i can't starting it up again by doing the same action ( shorting SMC_ONOFF_L ) .

If i connect the battery and unplug the charger , everything works normaly

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

Post the voltage on the SMC_ONOFF_L pad.

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

SMC_ONOFF_L = 3.44v

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

Without the battery, confirm the voltage of SMC_RESET_L (R5100, pin # 2).

This is an open-drain output so R5100 must be present to pull this hi-z line HIGH.

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

smc_reset_l = 3,37

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

This one will be tricky to monitor...when you short the ON/OFF pads with tweezers, do you see the SMC_RESET_L go low ?

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

okey, i'am using oscilloscope

when shorting ON/OFF ( R5115 ) SMC_RESET_L does not go low ( you didn't ask but PM_PWRBTN_L goes low )

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

Do you see SMC_RESET_L go low when powered off the battery and R5115 is shorted ?

If you short the open-drain output line SMC_RESET_L to ground, you should be able to mimic the ON/OFF button press.

If you manually short SMC_RESET_L to ground, does the logic board turn ON / OFF properly ?

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

No, even with battery or charger SMC_RESET_L does not go low when R5115 is shorted ! ( it should be ? )

With shorting SMC_RESET_L to ground the logic board start up
( by the way i think this is a manuel SMC RESET ? it has the same behavior as when i press SHIFT+CTL+OPTION + POWER BUTTON => it reset the SMC brief green light on the charger and logic board startup )

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

See attached.

BOTH inputs to the device @ U5110 must be LOW to drive the output low.

What is the voltage on SMC_LSOC_RST_L ?

I may have lost my way on this thread, when you use tweezers @ R5115 with the battery only - does the logic board turn ON / OFF normally ?

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

I may have expressed myself badly, that's why you're lost. Sorry!

You asked me in post #10 to short SMC_RESET_L to ground . So, i said that logic board turn on
this has the same behavior than SMC RESET with keyboard ( SHIFT+CTRL+OPTION +POWER_BUTTON ) the logic board turn too .

And yes, when using tweezers @ R5115 with the battery only the logic board turn on

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

Using only the external power adapter, what is the voltage of the following ?

PPBUS_G3H

Next, remove all power. Meter in resistance mode. Use the lowest scale on your meter (2k is ok).

We want to check if you have defective mosfets.

Measure the resistance of the following:

< see attached >

source (1-2) & drain (7-8-9-10)
source (1-2) & gate (3)
gate (3) & drain (7-8-9-10)

of Q7180.

This is a DUAL mosfet in a single package device so repeat the above tests for the 2nd mosfet.

source (4-5) & drain (7-8-9-10)
source (4-5) & gate (6)
gate (6) & drain (7-8-9-10)

Post your (logic board's) measurements.

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

Thanks for your patience :

PPBUS_G3H = 8,53 V

Q7180 is OK there is no short

source (1-2) & drain (7-8-9-10) = OL
source (1-2) & gate (3) = OL
gate (3) & drain (7-8-9-10) = OL

source (4-5) & drain (7-8-9-10) = OL
source (4-5) & gate (6) = OL
gate (6) & drain (7-8-9-10) = OL

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

Hi , any suggestion ?

[mon2]

Re: Macbook Air A1466 does not turn on when pluged

Can you confirm the voltage of PPVIN_G3H_P3V42G3H with only the adapter?

[delphi_firebird]

Re: Macbook Air A1466 does not turn on when pluged

Hello ,

PPVIN_G3H_P3V42G3H = 14.55v

than you for your time