macbook a2141 board 820-1700 no turn on

[dcs10]

Re: macbook a2141 board 820-1700 no turn on

it's late so going to bed , but will keep looking for USB D+ / D- pin on the pdf

and thank you for your patience mon2

regards

den

[mon2]

Re: macbook a2141 board 820-1700 no turn on

It is always wise to be rested when working with these tiny parts. Many of them are 0201 in size and they are very small and a slip of the meter lead can cause other headaches. I need to practice what I am preaching as well but always in a rush to get it done yesterday

When rested, start with the DIODE readings for the following:

USBC_XA_CC1
USBC_XA_CC2

These are called the CCx lines and each connector will have a pair -> which links to the local ACE controller.

The CCx lines are used to exchange the Power Delivery contracts. It is a known fact that these lines get damaged due to the hot removal of the external adapter. The kooky Type C connector can short the CCx line against the high voltage line used for the power delivery pin itself if the cable is pulled at a slight angle.

For a while, the CCx lines were not 20V tolerant. Now the latest power delivery controllers can handle even 28V surges without damage. I recall almost burning my hand from a similar case but that was a few years ago and was with PD 1.0 specs. Now they are 'more advanced' so let us hope for the best.

For the DIODE mode testing, RED meter to ground & BLACK meter lead to the CC1 pin. You could measure this @ C3113 and then again @ C3114.

Post the DIODE reading values.

The repeat for the next USB port, etc. and post the results.

See attached on where to measure.

What we are looking for are any possible bad DIODE readings which will indicate the ACE controller is likely damaged due to the high voltage surge from the external adapter. No power to the logic board for these tests - only the meter in DIODE mode.

[dcs10]

Re: macbook a2141 board 820-1700 no turn on

left side of macbook pro

top port
---------------
d+725 ohms

d- 725 ohms

bottom port
----------------
d+725 ohms

d- 725 ohms

right side of macbook pro


top port
---------------
d+725 ohms

d- 725 ohms

bottom port
----------------
d+725 ohms

d- 725 ohms

looks like their are no short on the ACE' controller ,mon2

whats next?

regards

den

[dcs10]

Re: macbook a2141 board 820-1700 no turn on

USBC_XA_CC1 .539 cb413
USBC_XA_CC2 .539 cb414


USBC_XA_CC1 .535 cb313
USBC_XA_CC2 .535 cb314


USBC_XA_CC1 .540 c3113
USBC_XA_CC2 .540 c3114


USBC_XA_CC1 .545 c3213
USBC_XA_CC2 .545 c3214


all done no shorts here !

regards

den

[mon2]

Re: macbook a2141 board 820-1700 no turn on

voltage reading @

1) PPDCIN_G3H ?

2) PPDCIN_XA_G3H_F ?

3) PPDCIN_XB_G3H_F ?

4) P3V3G3S_EN ?

5) PP3V3_G3H_T ?

6) PP5V_G3S (24mv?) check on enable for this rail @ P5VG3S_EN_R

7) P3V3G3H_EN

and review this thread:

https://boards.rossmanngroup.com/thr...-5v-dfu.61490/

[piernov]

Re: macbook a2141 board 820-1700 no turn on

T2 must be working before USB-C controllers can negotiate USB-PD 20V.

[dcs10]

Re: macbook a2141 board 820-1700 no turn on

T2 must be working before USB-C controllers can negotiate USB-PD 20V.

Hi piernov ,

what line powers the T2 chip ?


@mons 2 the inductor has not come yet so can i still power it up to check the
these

1) PPDCIN_G3H ?

2) PPDCIN_XA_G3H_F ?

3) PPDCIN_XB_G3H_F ?

4) P3V3G3S_EN ?

5) PP3V3_G3H_T ?

6) PP5V_G3S (24mv?) check on enable for this rail @ P5VG3S_EN_R

7) P3V3G3H_EN

regards

den

[piernov]

Re: macbook a2141 board 820-1700 no turn on

Schematics → Ctrl+F "SoC Power"

[dcs10]

Re: macbook a2141 board 820-1700 no turn on

cheers