820-01521-A MACBOOK AIR 13 RETINA A1932 GOES TO 20V AFTER 5 SEC AND DOESNT STARTS.

[2informaticos]

First of all, welcome to the forum!

If charger switches to 20V, USB-C area should be good.
Don't work there again, in similar case.

Q7065 is not important here, unless you have problems with the battery.
PPBUS_G3H can be checked at C7050; it is stable?

As always with T2 machine, start checking if is recognized in DFU mode.

 

[Baltaszar]

Hi again.. thanks for your time..

Kind of not stable at all.. check the image pls.. starts good.. after 6.3 sec aprox.. ups from 12.3 to 12.7..

In 15 seconds aprox.. starts to have noise or ripple.. as you can appreciate in images.

What could it be? Thanks.

BTW... can i duf this a1932 without another a1932?

 

[2informaticos]

Follow the tutorial linked on the forum.

HOW TO collection

I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...

boards.rossmanngroup.com

If PPBUS_G3H is not stable, check if all AWAKE and SLPS2R voltages are stable.

 

[Baltaszar]

Taken from schematic
VOLTAGE FROM OSCILLOSCOPE / VOLTAGE FROM MULTIMETER
PP1V8_AWAKE = 1.92v / 1.8021v no ripple.
PP1V2_AWAKE = 1.26v / 1.2007v no ripple.
PP3V3_AWAKE = 3.36v / 3.300v no ripple.
PP1V8_SLPS2R = 1.86v / 1.8035v no ripple
PP1V25_SLPS2R = 1.30v / 1.2497v no ripple
PP1V1_SLPS2R = 1.14v / 1.1005v no ripple..

Do you need others awake voltages? like
PPVDDCPUSRAM_AWAKE
PPVDDCPU_AWAKE
PP1V2_AWAKE_SOC_PCIEREFBUF_F
PP1V2_AWAKE_SOC_PLLCPU_F
and etc...

This was noted from the osci in 500mv/div.. a kind of noise of 0.02-0.06 was observed but.. if i go more mv or volts/div.. the noise was reducing... i think its part of the specs of my osci... but.. in the multimeter the reading was stable. no fluctuation at all (maybe +- 0.0002 v).. even the last digit.
Also, do you need osci graphics?

Thank you very much.

By the way.. about the "how to collection" what do i need to do exactly? all the steps ? or was for how to measure the voltages?

 

[2informaticos]

Forget the o-scope.
You may need to on it few times in a year maybe; for laptop repairs.

The machine should be detected in DFU mode, if all AWAKE and SLPS2R are present.

I meant to follow the steps from DFU tutorial, linked in that thread.

 

[Baltaszar]

Anyway.. i made the steps.. hehe

Trigger SMC_ONOFF_L (PMU_ONOFF_L):
I conect the power source and mac tries to start.. in the middle i "press" trigger the onof.. but nothing.. if i stay a few seconds the contact... it responses.. and the consume fall down.. (added powerz graphics)

Check PCH's RTC signals:
RTC_RESET_L : Goes from 0 to 3.007v.
PCH_SRTCRST_L : Not found on schematic
PCH_INTRUDER_L : from 0 to 2.730 v
PCH_INTVRMEN : Not found on schematic

At this point i see your mail.. about DFU XD

Checked.. i turned off the oscilloscope XD.. i think could be useful

 

[Baltaszar]

The machine should be detected in DFU mode, if all AWAKE and SLPS2R are present.

I meant to follow the steps from DFU tutorial, linked in that thread.

What if the client dont remember or didnt know the mac version? thanks

 

[2informaticos]

Try with what ever macOS available on other machine.
If not recognized, then try other machine, with different macOS.
The original client's macOS should be Mojave, or Catalina.

 

[Baltaszar]

Hi again. i get another pink macbook air with usb c port.. the target starts in dfu.. so i a try with "restore" but i get the error:


Error 4005

The OS Cannot be restored on this device.

Gave up waiting for device to transition from RestoreOS state to BootedOS State. [com.apple.MobileDevice.MobileRestore – 0xFA5 (4005)]

Theres another thing to do.. maybe is not the t2 chip.. could it be electrical reason? I try with "revive" options.. same result. Thanks in advance.

Btw i used original c cable from charger

Edit.. in the video i see logo when entering udf mode.. in this mac.. no video never at all..

 

[2informaticos]

What machine/board model is this last MacBook?

 

[Baltaszar]

The first mac A1932 EMC 3184... The last mac A2337 emc 3598. thanks

 

[Baltaszar]

a) In Q7065 in PPVBAT_G3H_CHGR_R i have 12.6v.. and the gates go from 12.6 to 4 or something volts... every 5 seconds.. it means.. five seconds 12v.. fiveseconds goes down.. five seconds goes high.. and so..

b) Q3100 (from u3100 CD3215A10) gets high temp..

This pulse its normal? that without battery.. with battery its almos 0 v.

Q3100 its normal to burn the alcohol?

Thanks again

 

[2informaticos]

"What machine/board model"
Board model is really important, to know which schematic consult.
And please, open separate thread for different repair.

Check the diode mode to ground around Q3100; compare with Q3200 values.
Forget Q7065 if PPBUS_G3H is stable.
If no battery connected, no need to check F7000 voltage.