MacBook Pro A1990 doest turn on

[mon2]

Re: MacBook Pro A1990 doest turn on

Post your voltage reading for PP3V3_G3H_RTC_X.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

Before the short the voltage on PP3v3_G3H_RTC_X was 3.3v.
Does this info helps in anything?

thanks

[mon2]

Re: MacBook Pro A1990 doest turn on

Is it no longer 3v3 ? This is a critical voltage.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey ,

I can measure it .
But why its important if i cant generate this voltage till i replace the U7650 ( PMIC) ?

[mon2]

Re: MacBook Pro A1990 doest turn on

It is ok if you have parts off the logic board. Proceed to replace.

The PP3v3_G3H_RTC_X is required to power the CD3215 controllers.

Rail is generated by U6960. Just thought to mention it.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

Finally the parts arrived and i am going to replace them tomorrow.
But i thought to check with you something.
As you remember i think that i burned U7650 ( TPS51980A PMIC ), and today i thought that maybe there is also a chance that maybe U7660 (CSD58873Q3D) also was ruined .
can you please share what is the impedance that should i get when i am measuring this transistor .
the Macbook is A1990A.
thanks

[Ksansan]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

Finally the parts arrived and i am going to replace them tomorrow.
But i thought to check with you something.
As you remember i think that i burned U7650 ( TPS51980A PMIC ), and today i thought that maybe there is also a chance that maybe U7660 (CSD58873Q3D) also was ruined .
can you please share what is the impedance that should i get when i am measuring this transistor .
the Macbook is A1990A.
thanks

There should not be a short between pin 1 and pin 6.
It should be hundreds of ohms

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2 and @Ksansan,

Here is an update
I replaced U7650 which i shorted and returned to ground zero .
Now , all the USB C ports were stuck on 5V and drawing between 370mA to 390mA.
From my corresponding with mon2 i started to replace U3200 ( CD3215C).

And now this is the situation :

U3100 and U3200 USB C ports are stuck on 5V and drawing 370mA-390mA
UB300 and UB400 USB C ports are stuck on 20.2V and drawing 110mA.

I measured all the LDO voltages from the CD3215 and also the PP3v3_G3H_RTC_x here are the readings :
note: in U3100 and U3200 PP1v1_LDO is missing.

U3100 :
PP3v3_LDO - 3.34v
PP1v8_LDOD-1.8v
PP1v8_LDOA-1.811v
PP1v1_LDO - 0v ( missing)
PP3v3_G3H_RTC_X- 3.38v
PP1v8_SLPS2R- 1.8v

U3200 :
PP3v3_LDO - 3.38v
PP1v8_LDOD-1.791v
PP1v8_LDOA-1.814v
PP1v1_LDO - 0v ( missing)
PP3v3_G3H_RTC_X- 3.38v
PP1v8_SLPS2R- 1.803v

UB300 :
PP3v3_LDO - 3.34v
PP1v8_LDOD-1.789v
PP1v8_LDOA-1.795v
PP1v1_LDO - 1.113v
PP3v3_G3H_RTC_X- 3.38v
PP1v8_SLPS2R- 1.786v

UB400 :
PP3v3_LDO - 3.34v
PP1v8_LDOD-1.789v
PP1v8_LDOA-1.818v
PP1v1_LDO - 1.121v
PP3v3_G3H_RTC_X- 3.38v
PP1v8_SLPS2R- 1.786v

I dont know what happened !! do i still have a problem with the U3200 ?
maybe i didnt solder it correctly?
please advice

[mon2]

Re: MacBook Pro A1990 doest turn on

Hi. See attached.

1) Start with removing all power. Meter in resistance mode (2k scale). Check the resistance to ground for the 1v1 LDO rail for the ports that are not working.

What are the readings for each CD3215 1v1 voltage rail ?

Next, place the meter in DIODE mode.

Then RED METER lead to GROUND.

BLACK METER lead to the 1v1 voltage rail. Reading ?

Repeat for each CD3215 stuck @ 5v and then for the working CD3215 devices.

DO NOT have power to the logic board during these tests.


2) Post the voltage reading for PP3V3_G3H.

reference:
https://repair.wiki/w/Charger_stuck_...nstead_of_20_V

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

Here are the measurements

U3100 :
PP1V1_LDO impedance is 198k, in diode mode 0.49v

U3200 :
PP1V1_LDO impedance is 202k, in diode mode 0.49v

UB300 :
PP1V1_LDO impedance is 201k, in diode mode 0.49v

UB400 :
PP1V1_LDO impedance is 198k, in diode mode 0.49v

The PP3V3_G3H_T is 3.34v .

thanks

[mon2]

Re: MacBook Pro A1990 doest turn on

Post the voltages on each pin of the SPI ROM used by the CD3215 (non-working) @ U2890.

See attached. You can measure at the resistors.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

here are the results for U2890 , DC measurements:

Pin1 TBT_X_SPI_CS_L : 3.3v
Pin2 TBT_X_SPI_MISO : 3.33v
Pin3 TBT_X_SPI_ROM_WP_L :0.726v
Pin4 GND : 0v
Pin5 TBT_X_SPI_MOSI: 0v
Pin6 TBT_X_SPI_CLK: 0.07v
Pin7 TBT_X_ROM_HOLD_L: 3.33v
Pin8 PP3V3_UPC_XB_LDO: 3.33v

thanks

[mon2]

Re: MacBook Pro A1990 doest turn on

Remove all power. Meter in resistance mode.

Check & post the resistance of

R3095

R3096

R3097

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

Will do , but unfortunately I could do it only tomorrow . Thank you a lot for your support.
By the way , is it normal that one side of the USB C controller is stuck on 20v and the other side is stuck on 5v ? Does it means that I succeed to replace U3200 , because the other side of the USB C port are now on 20v ?

[mon2]

Re: MacBook Pro A1990 doest turn on

U3100 & U3200 are paired together. They need to function together to allow for the 20V selection. Since this side of the USB C ports is stuck @ 5 volts, there is some issue.

From my understanding:

1) U3200 is the MASTER controller & U3100 is the SLAVE controller.

2) U3200 is looking to extract firmware from an external SPI flash device @ U2890. Presently, your CLK and MOSI (Master Out; Slave in) are showing the wrong voltages. It is possible that they are 0v because the MASTER controller gave up searching for the flash memory chip. TBD.

3) After the firmware is extracted from U2890, then this MASTER device will communicate with the SLAVE controller @ U3100 over the UART lines (TX & RX) to send out the firmware details to the slave device.

UPC_XA_UART_TX
UPC_XA_UART_RX

will be used.

If any of these fail, then the 1v1 LDO rail will not function.

To add to this, the CD3215 itself could be defective. Is your source for the part a known good vendor ? Just asking but basing this concern from assorted postings.

4) For the soldering, consider to flux the replaced part well, hot air the part in circles and use tweezers to nudge the corners till the part moves on its own. Then it should spring back into place, naturally. This is a great method to allow for any shorts to correct themselves underneath the BGA device. It is worth a go to try this process.

Apply aluminum foil onto the parts you wish to protect. Be sure there is no power to the board. Or use kapton (polymide) tape for the same purpose.

5) It is good to have the 20V on the other ports and that may be all we need to move forward, for now. Perhaps others have additional feedback.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

I ordered my parts from Louis Rossman store and also from beetstech, so no concern here.
I was wondering about the 20V on UB300 and UB400 only because they were also stuck on 5v and draw 380mA-390mA before the replacement of U3200.
I will measure the resistors tomorrow and will update you .
If I need to re-hot / re solder U3200 I will do it .
Thanks

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Apply aluminum foil onto the parts you wish to protect. Be sure there is no power to the board. Or use kapton (polymide) tape for the same purpose.

Question about this : The kapton didn’t succeed to prevent from the heat to “melt” the RF shield a little bit . Is it a problem ? Can I replace the shield ? And if I can, from where I can order it ?

Thanks

[mon2]

Re: MacBook Pro A1990 doest turn on

No need to replace the RF shield. Continue to use as-is.

[Ksansan]

Re: MacBook Pro A1990 doest turn on

I've got a damn power button that doesn't work.
That's bad!

[mon2]

Re: MacBook Pro A1990 doest turn on

Apple repairs...

https://www.youtube.com/watch?v=NWsgBqNuVEk