A1990 doesn't turning on

[OzNitzan]

Hello ,

I have A1990 2018 macbook pro . The MB number is: 820-01041A.
A little bit of water touched the USB C port of U3200 and U3100 ( i think that only in one of them ).
No trace of liquid damage .

Here is the situation:

At the beginning all the 4 USB C ports were stuck on 5V and draw 380mA - 400mA .
After power rail check and ACE LDO check i decided to replace U3200 .

The new situation is this :

USB C ports of UB300 and UB400 are stuck on 20v and drawing after a current cycle 110mA . I already checked SSD0 power rail and i am getting 2.5v.
i can also say that i have all the power rails including the PMU_ONOFF_L which is 3.38v ( the power sequence was taken from 820-01598). moreover in this case PP3V3_S5 is 1.329v and PP1v8_S5 is 0.44v however no short on those rails . PP3v3_s5 resistance to ground is 74Kohm and PP1v8_S5 is 23.33Kohm.
forgot to mention that all the ACE LDO voltage are present.

USB C ports of U3200 and U3100 are stuck on 5v and drawing 380mA - 400mA .
For those chips the 2 X 1.8v_LDO and the 3.3v_LDO are present however the 1.1v_LDO is missing.
PPBUS is present 12.6v and also PP3V3_G3H is present 3.34v.
I checked the resistance of C3104 and C3204 ( Use for CC1 and CC2 communication ) and both of them are 198kohm.
moreover i checked the CC1(USBC_XB/XA_CC1) and CC2 (USB_XB/XA_CC2) of those CD3215 in diode mode and got :
CC1 - 0.585v
CC2 - 0.59v

I also checked the ACE_I2C_lines and got the following values on R2834 and R2835 ( I2C_TBT_X_SCL and I2C_TBT_X_SDA ) Both of them are on 3.31v .

I also decided to check and compare QB400 and Q3100 and Q3200 .
Those chips as i see it are responsible to deliver 20v to the board ( PPDCIN_G3H).

the results on the working USB C , QB400 and QB300 :
1. UPC_TB_GATE1 : 26V ( FROM CD3215)
2. UNCONNECTED
3. UNCONNECTED
4. UPC_TB_GATE2 : 22.5V ( FROM CD3215)
5/6/7 : PP20V_USBC_TB_VBUS: 20.37V
8: PPDCIN_G3H: 20.37V

the results on the un working USB C , Q3100 :
1. UPC_XA_GATE1 : 10.83V ( FROM CD3215)
2. TP_Q3100_DRAIN: 5.11 V
3. UNCONNECTED
4. UPC_XA_GATE2 : 8.27V ( FROM CD3215)
5/6/7 : PP20V_USBC_XA_VBUS: 5.11V
8: PPDCIN_G3H: 5.11V

the results on the un working USB C , Q3200 :
1. UPC_XB_GATE1 : unable to measure ( FROM CD3215)
2. TP_Q3200_DRAIN: 5.11 V
3. UNCONNECTED
4. UPC_XB_GATE2 : 6.87V ( FROM CD3215)
5/6/7 : PP20V_USBC_XB_VBUS: 5.11V
8: PPDCIN_G3H: 5.11V


So anyone can please assist ?
why when i replaced U3200 the volatge of UB400 and UB300 was increased to 20v but U3200 and U3100 are still stuck on 5v ?
maybe i have a problem in the soldering ? maybe the call to replace U3200 was a mistake?
If you read this , please go to the last post. The board fell on the ground and bent a little bit. maybe you have an idea

 

[2informaticos]

First of all, welcome to the forum!

Always check power rails in diode mode, not ohm scale.
Switch to ohm scale only for very low values; usually under 0.010 reading.
Read here about correct way to do it.

HOW TO collection

I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...

boards.rossmanngroup.com

Disconnect everything from the board; test it alone on the desk.
Of course, keep the charger connected.

Where did you get the new CD3215 chip?
Does it have the same termination code?
B03 is not compatible with C00.

Check U2890 traces, solders and adjacent resistors.

 

[OzNitzan]

Hey ,

Thank you very much.

I got the new CD3215 from your store , bought 2 chips from you and two other from beetstech. But the soldered on is from your store.
yes , they have the same termination code C00.

I checked U2890 :

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

also checked resistors : R3095/R3096 and R3097 all of them are 15ohm and looks fine.
By the way ,general questions :
1. Is it normal that one side of USB C port show 20v and the other side show 5V ? And most important why it happened after the replacement of U3200?
2. How do i know if i replaced the right ACE controller ? maybe i had to replace U3100 ? In order to get 1.1v_LDO on U3100 ,do i need to get 1.1v_LDO on U3200 first ?

 

[2informaticos]

1V1 LDO appears only on the powered port.

Depending which block of CD3215 chip is affected, you can get 20V on other port.
In such case, may have bad chip on the input side.
It is still able to communicate with SMC (T2), but can't control the input.
That's the reason to get 20V on the other port.
If one CD3215 doesn't communicate with SMC, will not get 20V on any port.

Now try to replace U3100 too.

 

[OzNitzan]

Hey ,

When You say : " If one CD3215 doesn't communicate with SMC, will not get 20V on any port " , you mean that in the ACE controller pair , even if one of them is faulty , none of them will generate 1.1v LDO and this is why the 20v will not be generate? ( for example if U3200 is faulty and U3100 is fine so none of them will generate the 1.1v LDO )

And again for my knowledge : at the beginning all the USB C port showed 5v and draw 380mA-390mA . only when i replaced U3200 , UB300 and UB400 rise to 20v , but U3200 and U3100 are still stuck on 5v . why did it happened ? why U3200 is still stuck on 5v if its okay ?

If replacing U3100 will fix the macbook , the voltage will be 20v and how much current will it draw ?
will replace U3100 and keep you update

 

[2informaticos]

You should replace U3100 and see what happens.
Be sure to get good solders.

The behavior of USB-C ports depends of the internal problem of a CD3215 chip.

 

[OzNitzan]

Hey ,

Before replacing U3100 i looked once again on the trace to U2890 . Than i saw that U2890 is a little bit off its pads. Reflow it and U3100 and U3200 are now on 20v . Than unfortunately, the board fell on ground and bend a little bit . now all the USB C ports presents 5v and drawing 250mA .
Does it means that its over ?

 

[2informaticos]

Ooops, that's no good at all.
You may have knocked off components, or even broken solders under BGA chips.

 

[OzNitzan]

Any Ideas?

 

[2informaticos]

Inspect the board under microscope.
Unfortunatelly, this may be a lost cause...

 

[OzNitzan]

Hey ,

I checked the board today .
here is what i have till now :

First : all the USB C port are stuck on 5v and drawing 250mA.

1. All The LDO rails of each CD3215C are on, of course the LDO 1.1V is on for each ACE when its connected to power adapter.
2. PPBUS_G3H :12.3 v
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
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
Pin6: TBT_T_SPI_CLK: 1.152v
Pin7: TBT_T_ROM_HOLD_L: 3.34v
Pin8: PP3V3_UPC_TA_LDO: 3.34v
Pin9: GND

5.
I2C_TBT_T_SCL (RB034, pin #2)
I2C_TBT_T_SDA (RB034, pin #2)
the voltage is 0v

6.

I2C_TBT_X_SCL (R2834, pin # 2)
I2C_TBT_X_SDA (R2835, pin # 2)
the voltage is 0v

7.

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

Any Idea ?

 

[2informaticos]

Probably broken trace, or solders...