MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

[slimmy182]

Hello out there.

I purchased this mac MacBook Pro 13'' M2 chip, model A2338, logic board number 820-02773 as partially working. Seller give me an apple report saying: "Liquid spill on trackpad flat, BMU battery flat and logic board. Macbook starts only when connected to DC IN and show intermittent shoutdown".

Now that I got it is does not start at all, Amp mether shows 5V 0A on both usb-c.

Tearing down the logic board I can confirm there was liquid spill on the battery connector area and the battery flat. Liquid spill also on the trackpad connector and small amount on the antenna wifi connectors. I guess there was also a little moisture on the Q5800 side (referring to 820-02020 board view as 820-02773 is not present at this time).

The back side of the board is pretty clean, no sings of corrosion or cleaning.

The fact is that this moderboard was already cleaned from moisture, so I need to better check everything under microscope. Futhermore it seems to me that i'm hearing the famous clicking sound also in that board. But no components it's getting hot when plugged in.

I would be glad if somenone more skilled that me will help me troubleshotting this Mac to have it finally working. That would be really appreciated.
What I can start testing with my multimeter?

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Since the current draw is @ 0v and stuck @ 5v, start with a review of the USB Type C controllers (aka ACE controllers).

See attached.

Remove all power. Meter in resistance mode. Check the resistance across the white body parts = fuses.

Post your measurements.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Since the current draw is @ 0v and stuck @ 5v, start with a review of the USB Type C controllers (aka ACE controllers).

Many Thanks mon2!!

Cheking the two fuses nearby ACE controllers i've got continuity (no resistance)

Upon connecting to DC IN i've got 5.17V on both side of each one.

I also took those measurement (please mind that I'm using 820-02020 brd as reference):


voltage on PPBUS_AON on FP800
1 PPBUS_AON 12.3V
2 PPVIN_LCDBKLT_F 12.3V

voltage on PP3v8_AON
L5800
1 P3V8AON_VSW1 3.78V
2 PP3V8AON_PH1 3.78V

PP3v3_S2 voltage
LC710
1 P3V3S2_SW 0V
2 PP3V3_S2 0V

CD3217 support voltages

RP844
1 PP5V_S2 0V
2 PP5V_BKLT_D 0V

PP3v3_S2_UPC NOT ABLE TO LOCATE

C5320
1 PP1V25_S2 0V
2 GND

PPDCIN_AON_CHGR_R
C520C
1 PPDCIN_AON_CHGR_R 5.17V
2 GND



series of current sensing resistors
R5221 — 1.4 Ω

R5222 — 1.4 Ω

R5261 — 1.4 Ω

R5262 — 1.4 Ω

Upon investigating board on microscope I found this spot of corrosion, see attached. Mainly around JT200, Q5840, C5800, UD560 areas.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Any of these part w moisture could be related to the problem?

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Perhaps. Pour alcohol (IPA) and see if these sites can be cleaned up.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

I guess the voltage of each LDO rail is present on each of the CD3217 devices.

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

I think you are missing to check one more LDO rail at 1v1? Review the schematic. Not at my desk. It is the rail used for the bmc communication over the CCx lines.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

i think you are missing to check one more ldo rail at 1v1? Review the schematic. Not at my desk. It is the rail used for the bmc communication over the ccx lines.

cant find

those are the one I guess cheked

1 PP3V3_UPC0_LDO
2 GND

CF405
1 PP1V5_UPC0_LDO_CORE
2 GND

CF508
1 PP3V3_UPC1_LDO
2 GND

CF505
1 PP1V5_UPC1_LDO_CORE

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Ok, damn, upon checking voltages in renases chip area I deadly short the IC. Now the board is taking 5.16V and 0.43A, consuming 2.2W. That chip is pretty hot. Any advice how to find a replacement?
That would be different from RAA225501A A2338 2020 logic board I guess.

Mine is 501CR17 H150EDN 19054131, the other is 501CR0B.

damn damn damn damn

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Check the resistance to ground at the output of this regulator.

Post the measurement. If the resistance is low (and futile) then that explains why it is heating up.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Check the resistance to ground at the output of this regulator.

Could you please help me locate the output?

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Ok - found it - it is U5700.

All output pins need to be checked for their resistance to ground. Remove all power.

Measure for example,

pin #7 (LDO5)
pin #5 (PVCC)
pin #3 (UGATE1)

etc. - review the direction of the arrows on this component's library symbol in the schematic and measure each such pin to see if there is an excessive load.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Thank you so much for helping me.

U5700

5 P3V8AON_PVCC 5.2Ω

7 PP5V_AON 4.4Ω

Are pretty shorted. I'm facing difficult on measuring other IC output.

I found that A2338 M1 2020 820-02020 and A2338 M2 2022 820-02773 seems to share same U5700.

It isn't?

M2 and M1 images
.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Ok - found it - it is U5700.

All output pins need to be checked for their resistance to ground. Remove all power.

Measure for example,

pin #7 (LDO5)
pin #5 (PVCC)
pin #3 (UGATE1)

etc. - review the direction of the arrows on this component's library symbol in the schematic and measure each such pin to see if there is an excessive load.

U5700 replaced, now got 3.77V on P3V3AON. But the board is still taking 5.241V and 0A.

There is anything else I can check?

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

The primary rail is the USB type c adapter voltage which by default will be 5 volts. After a proper handshake over the bmc interface (CCx lines), the adapter will kick into 20volts.

Surprised it is 0 A current draw as downstream rails use this 5volt rail.

Is the meter accurate? Is the type c meter bidirectional in support? We initially had a crappy one that was unidirectional only so it reported the wrong current consumption of 0 A always.

Check the fuses.

Next, check the LDO rails on each ACE controller. The rails confirm that the ACE controllers are ok. Each controller must be working else you will be stuck at 5 volts. Review the LDO rails in the schematic for each ACE controller.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

The primary rail is the USB type c adapter voltage which by default will be 5 volts. After a proper handshake over the bmc interface (CCx lines), the adapter will kick into 20volts.

Surprised it is 0 A current draw as downstream rails use this 5volt rail.

Is the meter accurate? Is the type c meter bidirectional in support? We initially had a crappy one that was unidirectional only so it reported the wrong current consumption of 0 A always.

Check the fuses.

Next, check the LDO rails on each ACE controller. The rails confirm that the ACE controllers are ok. Each controller must be working else you will be stuck at 5 volts. Review the LDO rails in the schematic for each ACE controller.

As always, you were right. My type c meter is trusty, always use the same one and is bidirectional. Connecting to the transformer adapter side (not logic board side) I can detect 5.237V and 0.034A.
upon re-checking LDO rails and fuses for each ACE controller seems right. But I have not voltage on S2 rails.

Anyways I found schematis, boardview file and power supply diode mode reads pdf on famous chinese app. So from now my references are right for A2338 M2 820-02773 logic board.

PPDCIN_AON_CHGR_R 5V on both ports

LDO outputs

PP3V3_UPC1_LDO 3.44V
PP1V5_UPC1_LDO_CORE 1.58V

PP3V3_UPC0_LDO 3.44V
PP1V5_UPC0_LDO_CORE 1.58V

CD3217 support voltages

CC270
PP5V_S2 0V

RG2A0
1 PP3V3_S2_LDO 0V
2 PP3V3_UF790 0.34V

PP3V3_S2_USBLS1_ISNS 0V
PP3V3_S2_WLBT_ISNS 0V
PP1V25_S2 0V

RC714
P3V3S2_PWR_EN 0V
P3V3S2_EN 0V

PPBUS_AON_3V3S2_VIN_ISNS 12.30V

LC260
1 P5VS2TPS_PHASE 0V
2 PP5V_S2 0V



P5VS2_PWR_EN_RC 0V

I feel like UD600 could be damaged…

PP1V5_LDOINT_MPMU 1.48V

PP17V0_LDOIN 3.30V

[mon2]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

PP3V3_UPC1_LDO 3.44V
PP1V5_UPC1_LDO_CORE 1.58V

PP3V3_UPC0_LDO 3.44V
PP1V5_UPC0_LDO_CORE 1.58V

To me, the PP3V3_UPCx_LDO rail outputs seem high. These should be close to 3v3 according to the schematics.

For now, let us ignore this.

Remove all power. Meter in resistance mode. Check the resistance to ground at each inductor / coil on the board. Each such coil is linked to a local buck regulator so we are checking to see if there is a low resistance on the respective power rail. Often linked to a shorted part; ideally a shorted cap.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Remove all power. Meter in resistance mode. Check the resistance to ground at each inductor / coil on the board. Each such coil is linked to a local buck regulator so we are checking to see if there is a low resistance on the respective power rail. Often linked to a shorted part; ideally a shorted cap.

Thank you. Upon cheking, no low resistance found at each inductor / coil on the board.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

These are the measures I take in diode mode. Mine in red, black one as reference.

I'm not able to find any problem by myself.

[slimmy182]

Re: MacBook Pro 13'' M2 A2338 get 5V 0A does not boot. 820-02773

Any hint would be really appreciated