Hello ,
I have a MacBook Pro A1990 , year 2018 board number : 820-01041A.
The speakers and the microphone of the Mac are not working for some reason.
I do have sound through a Bluetooth device or when I connect a headphone plus microphone to the jack 3.5mm input.
Can anyone give me some direction on how to debug it on board?
thanks
noz_1974
Senior Member
Last Activity: 03-26-2023, 10:14 AM
Joined: 11-27-2021
Location: Tel Aviv
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MacBook Pro A1990 No Audio ( Speakers and Microphone)
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Re: MacBook Pro A1990 doest turn on
Hey ,
I meant short path to ground on my upper post
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Re: MacBook Pro A1990 doest turn on
Hey mon2,
Yes you right, and i think that we actually meant to the same thing.
but you already few steps ahead.
I forgot that i measured the resistance on CHGR_RST_IN_R and CHGR_RST_IN , and i got high resistance around 326kohm. It means that i dont have a short path to CHGR_RST_IN from the U7000 and i also dont have a short path to CHGR_RST_IN_R ( UPC_PMU_RESET) from the PMU (7800) and from the CD3215C chips. [B]Are you agree ?[/B]
This only leave us with a problem on U6940 , and to check this scenario...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey,
The voltage on CHGR_RST_IN is 0V.
which means that if i will remove R6940 and i will get 3.3v on pin10 of U6940 than U7000 is faulty.
If i will still get 0V ( after removing R6940 ) than i need to remove also R6941 which leads to U7800 ( the PMU) and to all the CD3215C . If the voltage will stay 0v than U6940 is faulty , otherwise if the voltage will go up to 3.3v it means that the problem might coming from a short under the CD3215C or from the PMU . And because its a short to ground , so i guess...Last edited by noz_1974; 02-13-2022, 03:08 PM.Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Confirm that U6940 is being powered. Check the voltage on [B]PP3V3_G3H_RTC_X[/B]. - [B]The Voltage is 3.36 v[/B]
While there, check the voltage of pins 3 & 4 of U6940. -
[B]the pin voltage is also 3.36V
PMU_ONOFF_L : 3.36v
PMU_RSLOC_RST_L: 3.36v[/B]
Check that this value matches BOTH sides of R4911. [B]both sides are 3.36v[/B]
The resistance to ground of [B]CHGR_RST_IN_R[/B] is too low.
Remove the resistor @ R6940 and then check the resistance again for...Last edited by noz_1974; 02-13-2022, 01:16 PM.Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey ,
CHGR_RST_IN and CHGR_RST_IN_R are on 0v.
the resistance to ground of CHGR_RST_IN_R is 54ohm.
VDDA and VDDP of U7000 are on 5V.
And thanks again
enjoy the stove time , sorry but i an not familiar with this expression unless you mean lunch
Last edited by noz_1974; 02-13-2022, 11:13 AM.Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Value of PP3V42_G3H ?
[B]I dont have this net in my board[/B]
Value of SMC_RESET_L ?
[B]Also dont have this net in my board , but i found:
SMC_RSMRST_L = 0v
SMC_SYSRST_L = 0v[/B]
Post the voltage readings for the SMC_I2C SDA & CLK lines (I2C_PWR_SCL and I2C_PWR_SDA)
[B]The voltage for those lines is flactuating between 1.784v-1.8v .
i dont think that they are suppose to be 3.3v because they are pulled up to PP1V8_SLPS2R but maybe i am wrong.[/B]
...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
[B][/B]
3) U2890 flash - each pin
Pin1 TBT_X_SPI_CS_L : 3.3v
Pin2 TBT_X_SPI_MISO : 3.33v
Pin3 TBT_X_SPI_ROM_WP_L :3.34
Pin4 GND : 0v
Pin5 TBT_X_SPI_MOSI: 1.434v
Pin6 TBT_X_SPI_CLK: 1.08v [B]( low than before) [/B]
Pin7 TBT_X_ROM_HOLD_L: 3.33v
Pin8 PP3V3_UPC_XB_LDO: 3.33v
4) UB090 flash - each pin
Pin1: TBT_T_SPI_CS_L : 3.34v
Pin2: TBT_T_SPI_MISO: 3.34v
Pin3: TBT_T_ROM_WP_L : 3.34v
Pin4 : GND
Pin5 : TBT_T_SPI_MOSI: 1.51v
...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey mon2,
Have you noticed that the values of UB090 and U2890 are little bit different than before ?
moreover , i think that i see small fluctuation on the SPI_CLK for both of them .Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey Mon2,
The LDO rails are present for each component.
same values as before ....Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey @mon2,
please see my results in bold .
Moreover i checked diode mode for the CC1 and CC2 lines:
U3100 and U3200 :
CC1 : 0.424
CC2 : 0.472
UB300 and UB400 :
CC1 : 0.469
CC2 : 0.421
thanks...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Will Post and update.
Will see, thanks for the link...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
I am not familiar with this show ....Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Yes i see, but does it means that if UB300 is good so i will get 1.1V LDO even if this USB C port is taking 5v .And the reason for not getting the 20v is because that we have other CD3215 which is faulty ?...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Now i am getting 5v on all USB C ports, and drawing 250mA.
Lets take for example that U3200 is faulty , Does it means that if i will check UB300 and UB400 LDO rails i will get all four of them ( 2x1.8 , 3.3v and 1.1v) even that the voltage is 5v?...Leave a comment:
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Re: MacBook Pro A1990 doest turn on
You Know Fauda...
Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey ,
I am so depressed right now.
I will check it first thing on Sunday and will update you.
I cant believe that i touched the 20v and than this tragedy .
And once again , i couldnt do it without you . Thanks alotLeave a comment:
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Re: MacBook Pro A1990 doest turn on
Hey mon2,
You were right but still there is no happy end.
apparently U2890 was a little bit off from its pad, didnt see till now.
I brought it back to place and U3200 and U3100 presented 20v but draw only 70mA.
Than a terrible accident happened, the board fell on the ground and bend a little bit. Now the voltage on each USB C is 5V and drawing 250mA.
I dont know what do to now
, is this the end?
Last edited by noz_1974; 02-10-2022, 07:00 AM.Leave a comment:
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Re: MacBook Pro A1990 doest turn on
Thanks ,
Few more questions :
1 . What will be to final reading that i suppose to see ? 20v which draw how many amps?
2. why not to try to replace U3100? you think that because U3200 is the master and its doesnt present 1.1V_LDO so he is the faulty one ? Can it be a situation which U3200 will show 20v and U3100 will show 5v ?
3. In order to get 1.1v_LDO on U3100 ,do i need to get 1.1v_LDO on U3200 ?
4. And for my good feeling , that i didnt do something stupid . The fact that UB300 and UB400 were on 20v after...Last edited by noz_1974; 02-09-2022, 01:16 PM.Leave a comment:
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Re: MacBook Pro A1990 doest turn on
[B]About 2[/B] : Did you saw the photo that i sent about the pads below U3200 , one of the pads #71 which connected to the TBT looks a little bit not fully soldered. the name of the net : USBC_XB_AUXLSX1 , attached the photo once again ( third on the right column ) the first pad is gnd also little bit fishy.
[B]About 3[/B] : all the caps are there , no liquid damage.
[B]About 3a[/B] : great idea will try that.
[B]About 3b[/B] : also great idea will try it firstRe: MacBook Pro A1990...
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