Macbook A2337 5V

[Instafixx]

Hello,
Namaste!

I have a Macbook A2337 820-02016 stuck at 5V.

History : Customer plugged in a 3.5MM jack supposedly from a large audio system at an auditorium and the Machine was spot dead.

PPBUS_AON is cycling from 11.2 to 12.2V.

Initial checks reveal PP5v_S2 is missing with 0V. No shorts found on this rail but.

The enable pin P5VS2_EN is also at 0V. I feel its U8100.
Anyone has an idea regarding this ?

[Instafixx]

Re: Macbook A2337 5V

Hello,
Namaste!

I have a Macbook A2337 820-02016 stuck at 5V.

History : Customer plugged in a 3.5MM jack supposedly from a large audio system at an auditorium and the Machine was spot dead.

PPBUS_AON is cycling from 11.2 to 12.2V.

Initial checks reveal PP5v_S2 is missing with 0V. No shorts found on this rail but.

The enable pin P5VS2_EN is also at 0V. I feel its U8100.
Anyone has an idea regarding this ?

Update - Reballed the U8100 - Still the Same.
Replaced the U8100 from a donor baord. Still the same issue.


Any guidance will be really helpful.

[mon2]

Re: Macbook A2337 5V

Remove F5200 and then check the voltage to ground of PPVBAT_AON_CHGR_REG.

Post the measurement.

With the Type C power supply stuck @ 5v means that the CD3217 ACE controllers have a fault. Need to check the local LDO rails on each to see if they are present.

Same case as all other CD321x controllers that fail to negotiate to 20V power delivery contract...review the repairwiki articles by @Piernov and others on how and when 20V is selected.


https://www.logi.wiki/index.php?titl...ootup_Sequence

[Instafixx]

Re: Macbook A2337 5V

Remove F5200 and then check the voltage to ground of PPVBAT_AON_CHGR_REG.

Post the measurement.

With the Type C power supply stuck @ 5v means that the CD3217 ACE controllers have a fault. Need to check the local LDO rails on each to see if they are present.

Same case as all other CD321x controllers that fail to negotiate to 20V power delivery contract...review the repairwiki articles by @Piernov and others on how and when 20V is selected.


https://www.logi.wiki/index.php?titl...ootup_Sequence

Pin #1 of F5200 after removing has 12.3V

[mon2]

Re: Macbook A2337 5V

Is it stable ?

Remove all power. Meter in resistance mode.

Check the resistance to ground of downstream side (Pin #2) of the removed fuse @ F5200.

Post the measurement.

[Instafixx]

Re: Macbook A2337 5V

Is it stable ?

Remove all power. Meter in resistance mode.

Check the resistance to ground of downstream side (Pin #2) of the removed fuse @ F5200.

Post the measurement.

Yes. Its a stable 12.3V.

Meter in 2K Mode - Red Probe on Ground. Value is .490

[mon2]

Re: Macbook A2337 5V

So you have 490 ohms to ground resistance on the downstream / consumer side of this PPBUS_AON power rail. That is a low reading.

Do you have an adjustable power supply that can support 1 volt (not higher) for voltage injection. Would you have a thermal camera?

The shorted part may heat up but the resistance may not be low enough for this method but worth testing.

[Instafixx]

Re: Macbook A2337 5V

So you have 490 ohms to ground resistance on the downstream / consumer side of this PPBUS_AON power rail. That is a low reading.

Do you have an adjustable power supply that can support 1 volt (not higher) for voltage injection. Would you have a thermal camera?

The shorted part may heat up but the resistance may not be low enough for this method but worth testing.

When using another meter and setting it to the Omega Sign. The reading starts at 5.2M and keeps going down. (Held for about a minute at it came till 1.9M and then i stopped).

Yes i do have a adjustable power supply to inject Voltage.

Sadly - i dont have a thermal camera.

But the board in general did not heat up at any particular place - apart from the CPU

[mon2]

Re: Macbook A2337 5V

So this rail is not shorted.

Check the voltage to ground of the CPU power rail. Checking if the CPU is shorted.

Also consider to use DIODE mode reading of the same test point.

[Instafixx]

Re: Macbook A2337 5V

So this rail is not shorted.

Check the voltage to ground of the CPU power rail. Checking if the CPU is shorted.

Also consider to use DIODE mode reading of the same test point.

This is an M1 board. Still familiarising with myself. Which rail do i check ?

[Instafixx]

Re: Macbook A2337 5V

So this rail is not shorted.

Check the voltage to ground of the CPU power rail. Checking if the CPU is shorted.

Also consider to use DIODE mode reading of the same test point.

PP0V805_S1_VDD_FIXED at Pin #1 of C7821 is 1.6 Ohms.
Do you think its the U7700?

[Sacred0489]

Re: Macbook A2337 5V

Hello i hope you have a great day i have a 820_02016 (a2337) When I connect the usb charger the voltage oscillates between 3 volts then it goes to 5 volts it reaches 20 volts and then the cycle starts again I have checked PPBUS_AON and it has 12.30 volts but it is intermittent while PP3V8_AON_VDDMAIN has 3.8 volts I already used the U301 programmer for this model since I have seen that it could be the problem but nothing, could you help me thanks

[jorgea380]

Hi I have the exact symptoms, did you ever find the problem?

[Instafixx]

Nope. Had to go for a motherboard replacement.

[kevingill]

Just had this fault on a MacBook M1.
It was the headphone jack board that was faulty and bringing down the whole board.
Unplugged the connector and the MacBook boots.
Couldn't see anything obviously wrong with the board, but going to order a replacement headphone jack board.