MacBook Pro A1990 doest turn on

[Ksansan]

Re: MacBook Pro A1990 doest turn on

No, that's not our method!

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Remove all power. Meter in resistance mode.

Check & post the resistance of

R3095

R3096

R3097

Hey @mon2,

the resistance of those resistors is: 15 ohm for each one of them,
as in the schematic.

thanks

[mon2]

Re: MacBook Pro A1990 doest turn on

The resistance values are good. Do they look to be without damage as far as soldering is concerned ? Just need to be sure that the flash memory device is able to reach these resistors.

When you connect the power adapter onto one of the non-working CD3215, what is the current draw showing ? You are stuck @ 5 volts and both of these ports have been tested ? The master & slave ?

What is the voltage on the 1v1 LDO rail for the non-working ports ?

You may have a firmware fault for the U2890 IC.

After the above, use the side that is working and post the voltage readings for the ROM on that side. I believe there will be a local rom there as well - my schematic database is having issues but will check it later to confirm the location for the ROM that is local to the other ports.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

1. The resistors are looking good and not damaged.
2. The faulty CD3215 are stuck on 5.11v-5.12v and drawing 380mA - 390mA. master and slave.
3. The 1.1 LDO rail is missing for the slave and the master of the non-working ports.
4. The ROM chip for the working USB C port is UB090. Those ports are stuck on 20.2v and drawing 110mA. The voltage values for the UB090 are:

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: 1.48v
Pin6: TBT_T_SPI_CLK: 1.186v
Pin7: TBT_T_ROM_HOLD_L: 3.34v
Pin8: PP3V3_UPC_TA_LDO: 3.34v
Pin9: GND

few notes :

1. The Voltage on the working USB C ports was changed to 20.2v only after replacing the CD3215 ( U3200) before that those ports were also stuck on 5v and draw 380mA-390mA .

2. the Computer was shut down after that a little bit of water touch the USB C port ( of the faulty CD3215) , this is why i dont think that its a firmware problem , but you are the expert ( can the firmware be damaged from this kind of accident?).

3. Lets say that the CD3215 is faulty , how can i know if its the U3200 or U3100 that is faulty ?

thanks

[mon2]

Re: MacBook Pro A1990 doest turn on

My schematic service is having connection issues.

According to the repairwiki on this topic, you may have a fault on the PP2V5_NAND_SSD0 rail.

See the last case here:

https://repair.wiki/w/A1990_2018-201...ar_MacBook_Pro

Measure and post the voltage of this power rail.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

The voltage on PP2V5_NAND_SSD0 rail is 2.524v , no short.

[mon2]

Re: MacBook Pro A1990 doest turn on

Voltage value on PPBUS_G3H ? Use the ports that are @ 20V.

3. Lets say that the CD3215 is faulty , how can i know if its the U3200 or U3100 that is faulty ?

When you attach the power adapter, does the current cycle from 0 to xx mA ?

Test both of the non-working ports to see if there is a difference in their behaviour.

For the above PPBUS_G3H measurement, use the side that appears to be working. Just not sure if you need the non-working side to be working to move forward.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

The voltage value on PPBUS_G3H is 12.6V.

[mon2]

Re: MacBook Pro A1990 doest turn on

With this good PPBUS_G3H value, proceed to check the voltage on each and every coil on the logic board.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

1. The PPBUS_G3H for all off the USB C ports is 12.6v.
2. When i attach the power adapter to the non-working ports i dont see any current cycle , i draw 380mA-390mA but maybe i have a slow USB C volt meter.
3. From Louis Rossmann video i need all the USB C to work in order to turn on the MacBook.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

With this good PPBUS_G3H value, proceed to check the voltage on each and every coil on the logic board.

From which port to connect the power adapter? does it matter?

[mon2]

Re: MacBook Pro A1990 doest turn on

I would use the 20v group.

The ISL9240 is a buck / boost regulator.

When you feed it 5v (non-working ports) - this chip boosts the voltage to the desired PPBUS_G3H value.

When it is 20v (working ports) - this chip lowers the voltage to the desired PPBUS_G3H value.

However, the current that can be supported will be higher when you start with the higher voltage and lower it using the BUCK mode of the regulator.

So use the 20v side.

[mon2]

Re: MacBook Pro A1990 doest turn on

Have you tried the SMC Bypass mode ? Press the ON switch on your keyboard and plug in the power adapter. Personally recommend that you use a power bar to turn on the adapter - hate the hot-swapping of the Type C connectors. Keep the ON/OFF button pressed for like 10 seconds. Does this make a difference on the current draw from the side that is ~ 0.1A @ 20V ?

Post the voltage readings on both sides of R3041 & R3042

Remove all power. Meter in resistance mode.

Check the resistance to ground of capacitor C3104.

Check the resistance to ground of capacitor C3204.

These are the caps on each 1v1 voltage rail and are used for the BMC line (CC1/CC2) communication. These rails are @ 0v on the non-working side - why?

Try the non-working ports again but flip the adapter cable to test the communication from the other side of the type C connector blade.

Any difference on the voltage that is negotiated ?

Perhaps your CD3215 @ U3100 is damaged but early to say.

If you feel ambitious, you could hot air off the SPI flash that IS working and swap onto the side that is NOT working. Only to test if the contents of the flash chip are the key to get that side to work. Only a suggestion.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

With this good PPBUS_G3H value, proceed to check the voltage on each and every coil on the logic board.

Hey mon2 ,

I measured the voltages on the coils.
also i measured the resistance without power.

The voltages on the coils are:

For all the coils near the CPU the voltage is zero volt ( 0v).

L7410- resistance to ground ( 4.8ohm)
L7420- resistance to ground ( 4.8ohm)
L7211- resistance to ground ( 2.4ohm)
L7221- resistance to ground ( 2.3ohm)
L7231- resistance to ground ( 2.3ohm)
L7330- resistance to ground ( 14.4ohm)
LA340- resistance to ground ( 1.7ohm)
LA640- resistance to ground ( 1.7ohm)
LA650 - resistance to ground ( 1.7ohm)
LA350 - resistance to ground ( 18.9ohm)
LA300- resistance to ground ( 292 ohm)


L9081 and L9080 - PP2v5_NAND_SSD0 - 2.5v
L9020 and L9021 - PP0V9_SSD0 - 0.9v
L9030 - PP1V8_SSD0 - 1.8v

LB700 - P5UVSBCT_LL - 0v resistance to ground 13.4K
L7660 - PP3V3_G3H_T - 3.3v resistance to ground 100K
L7660 - PP3V3_G3H_T - 3.3v resistance to ground 100K
L7600-PP5V_G3S - 5v resistance to ground above 25k

L8102-PP0V95_S0_CPUVCCIO - 0v resistance to ground above 49ohm
L7030 - CHGR_PHASE1 - 12.48 resistance to ground 200K
L7701 - P1V2_PHASE - 0V resistance to ground 138ohm
L8410 - PPVIN_S0SW_LCDBKLT- 0v resistance to ground above 300k
L6961 - PP3V3_G3H_RTC_REG - 3.34v resistance to ground above 50k
L6960 - PP3V3_G3H_RTC_REG - 3.34v resistance to ground above 50k


coils from the other side:

LA900 - PP1V8_GPU -0v
L7700 - P2V5S3_REG- 0v
L3500- P5VUSBC_X_LL - 0v

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Remove all power. Meter in resistance mode.

Check the resistance to ground of capacitor C3104.

Check the resistance to ground of capacitor C3204.


.

The resistance on those capacitors is 198K.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey mon2 ,

I also followed the power rail sequence from 820-01598 data sheet that i found.
I have all the rails up to the stage of : SMC BEGINS PWRBTN MONITORING.
THE PMU_ONOFF_L is 3.38v but :
1. PP3V3_S5 is 1.329v
2. PP1v8_S5 is 0.44v.

[mon2]

Re: MacBook Pro A1990 doest turn on

THE PMU_ONOFF_L is 3.38v but :
1. PP3V3_S5 is 1.329v
2. PP1v8_S5 is 0.44v.

Remove all power.

Measure and post the resistance to ground for each of these rails.

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Hey @mon2,

I 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 :
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

Is it helpful in any way?

[noz_1974]

Re: MacBook Pro A1990 doest turn on

Remove all power.

Measure and post the resistance to ground for each of these rails.

the resistances are:

For PP3V3_S5 - 74K
For PP1v8_S5 - 23.33K

[mon2]

Re: MacBook Pro A1990 doest turn on

The resistance values are good.

Place the meter in diode mode.

Remove all power. Red meter probe to ground.

Black meter probe to CC1 pin of the cd3215. Value?

Repeat for the CC2 pin.

Repeat for each cd3215. Post the measurements.