MBP A1989 No Power 5.1V .025-.03MA

[SugamaGoc]

Hello, I purchased an A1989 as for parts & not working a while ago and after a few weeks of troubleshooting would greatly appreciate any help that anyone here could give me.

I'll try to list as much info about the board as I can:

The machine without the battery connected draws 5V and .025mA.
PPBUS_G3H is stuck at ~1V. Sometimes it dips below this momentarily
I2C_PWR_SCL - 0V
I2C_PWR_SDA - 0V

3V3_G3H_RTC is missing as well, because U6960 isn't being powered &
CHGR_EN_MVR is not present as well

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

Meter in resistance mode.

Remove all power / no battery.

Check the resistance to ground on PPBUS_G3H.

What is the reading?

Next, remove the fuse on this rail. Power up again. Is PPBUS_G3H higher before the removed fuse?

Post the voltage before the fuse once the fuse is removed.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

PPBUS_G3H is reading ~1M ohms to ground

PPBUS_G3H is higher after removing the fuse, The voltage starts at 2 and then decreases. Once the voltage goes below ~1V, the voltage jumps back up to 2V and the cycle repeats.

Similar to what it was doing before, but now instead of jumping up to 1.1, it goes to ~2V.

Thank you very much for the reply

What do I test next?

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

See attached.

1) What are the voltage readings for pins # 2 & # 3 of the battery connector? Remove the battery so we can review the true readings of these communication lines (SDA & SCL). Red meter probe on the signal to measure; black to ground (shield is ok).

2) Measure the voltage of the pull-up voltage rails. Post the readings.

3) Remove all power -> meter in resistance mode. Check the resistance to ground of the same pins # 2 & # 3 of the battery connector. We are checking to see if the ESD diode @ D6950 is halting the I2C / SMBUS communication lines.

4) U7000 (ISL9240) is a buck / boost regulator. If 5 volts is fed into the device, this regulator will spit out a boosted voltage of ~12 volts to kickstart the motherboard. Respectively, when all is well, the USB Type C adapter will power the logic board @ 20V once the power delivery contract is selected by this working logic board. Then with a 20V INPUT from the external adapter, this U7000 device will switch into a buck converter mode and will LOWER the input voltage to again ~12v6 (need to check the actual value but is around this range).

In your case, you do not have anything close so ISL9240 may be defective. This is a tiny WLCSP device and requires precision microsoldering. Before we conclude this, check around to look for obvious damaged parts; liquid damage.

We also need to confirm:

a) what is the INPUT voltage @ PPDCIN_G3H ?

b) Remove all power. Meter in lowest resistance mode. Check the resistance of each current sense resistor that are highlighted. It is vital that the resistance of the series resistors match the schematic. If the part is missing, the ISL9240 will shut down immediately to protect potential damage.

Use the boardview file for this logic board -> locate the resistors -> measure their resistance.

Post the readings.

Again - NO POWER when checking resistance.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

1) The voltage for pins 2 & 3 on the battery connector is 0V, but it periodically jumps up to .120V

2) PP3V3_G3H_RTC is 0V, PP1V8_SLPS2R is 0.001V

3) Resistance to ground of those same pins is 3.9M ohms.

4a) PPDCIN_G3H voltage is 5.1V

b)
R7062 is ~53ohms, this does not match the schematic. How did this happen?
R7061 - 1.1ohm
R7021 - .8ohm
R7022 - .8ohm

Thanks

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

Remove R7062 off the board carefully without too much air pressure since it is tiny and can fly away or disturb nearby parts.

Check the resistance again if this resistor.

If required, replace it with another but source a 1% accurate part. Then check the resistance again in circuit. Then power up to check ppbus_g3h voltage (without the fuse).

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

Remove R7062 off the board carefully without too much air pressure since it is tiny and can fly away or disturb nearby parts.

Check the resistance again if this resistor.

If required, replace it with another but source a 1% accurate part. Then check the resistance again in circuit. Then power up to check ppbus_g3h voltage (without the fuse).

I replaced the out-of-spec resistor with one that matches the value on the schematic when measured on the board. However, the PPBUS_G3H voltage is the same as it had been before without the fuse.

So now I'm not sure what to do next.

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

Check the resistance to ground of the mosfets you can see north of U7000 in the partial schematic.

We are checking for possible shorted caps.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

Check the resistance to ground of the mosfets you can see north of U7000 in the partial schematic.

We are checking for possible shorted caps.

For Q7040:
I checked the resistance to ground of PPVBAT_G3H_CHGR_REG, which is just ppbus_g3h, and there was no short.

There was also no short between CHGR_GATE_Q4 and any of the other terminals of the mosfet, or one between CHGR_GATE_Q3 and any other terminal

I did the same tests on Q7030, and found the exact same thing.

Is that what you wanted me to test? If so then yeah, unfortunately I was unable to find anything :/

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

Update...proceed in this order:

1) we need to review the workings of your CD3215 devices first - the rest will follow.

2) see here:

https://logi.wiki/index.php/CD3215_Bootup_Sequence

3) so start with each ACE controller = CD3215 and review the LDO rails. Review the voltages on each and post their values here.

4) Do you see different current draw on other ACE controller ICs ? Do check the flipside of the Type C connector (ie. flip the adapter cable by 180 degrees to test again).

hold the balance of the mosfet tests @ U7000 for later. The above testing takes priority.

Confirm the dual mosfets Q7030 & Q7040 are ok by checking their resistance across their own pins.

So you will be checking the resistance between:

Q7030 - mosfet 1 / 2 :

source & drain
source & gate
gate & drain

post each measurement and the meter scale used for the test.

Then skip to mosfet 2/2 inside the same package and repeat.

Then proceed to test Q7040. We want to be sure the 2 x dual mosfets are ok by reviewing their resistances.

It is quite possible that ISL9240 (U7000) requires to be replaced.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

Update...proceed in this order:

1) we need to review the workings of your CD3215 devices first - the rest will follow.

2) see here:

https://logi.wiki/index.php/CD3215_Bootup_Sequence

3) so start with each ACE controller = CD3215 and review the LDO rails. Review the voltages on each and post their values here.

4) Do you see different current draw on other ACE controller ICs ? Do check the flipside of the Type C connector (ie. flip the adapter cable by 180 degrees to test again).

hold the balance of the mosfet tests @ U7000 for later. The above testing takes priority.

Confirm the dual mosfets Q7030 & Q7040 are ok by checking their resistance across their own pins.

So you will be checking the resistance between:

Q7030 - mosfet 1 / 2 :

source & drain
source & gate
gate & drain

post each measurement and the meter scale used for the test.

Then skip to mosfet 2/2 inside the same package and repeat.

Then proceed to test Q7040. We want to be sure the 2 x dual mosfets are ok by reviewing their resistances.

It is quite possible that ISL9240 (U7000) requires to be replaced.

Okay, so I tested the rails as per the wiki:
PP20V_USBC_XB_VBUS - 5.142V
PP3V3_UPC_XB_LDO - 3.291V
PP1V8_UPC_XB_LDOA - 1.819V
PP1V8_UPC_XB_LDOD - 1.802V
PP1V1_UPC_XB_LDO_BMC - 0V

Voltage and current draw is also identical across all CD3215s
Initially I never thought to test them because since PP3V3_G3H_RTC isn't present in the first place

Q7030 - Right Mosfett - Resistance between:

Source (GND) to Drain(CHGR_LX1) - 70kOhms
Drain to Source - .73Mohms

Source(GND) to Gate(GATE_Q2) - 77KOhms
Gate to Source - 1.95Mohms

Gate to Drain - 3.2Mohms
Drain to gate - 2.2Mohms

Q7030 - Left Mosfett :

Source(CHGR_LX1) to Drain - .67M
Drain to Source - .64M

Source to Gate - 80kohm
Gate to source - 2Mohm

Drain to gate - 1.91Mohm
Gate to drain - 5Mohm

Now for Q7040 - Left Mosfet :
Source(GND) to Drain(CHGR_LX2) - .587Mohm
Drain to Source - .73Mohm

Source(GND) to Gate(GATE_Q3) - 77kohm
Gate to source - 1.4Mohm

Gate(Q3) to Drain(CHGR_LX2 - 2.3Mohm
Drain to gate - 2Mohm

Right mosfet
Source to Drain - 90kohm
Drain to Source .694Mohm

gate to drain - 5.7Mohm
drain to gate - 2Mohm

gate to source - 2.3Mohm
source to gate - 80Kohm

Are any of these values irregular?
Sorry for the delay and thank you again

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

PP1V1_UPC_XB_LDO_BMC - 0V

Do you see this on each USB type c port? Even if you flip the power cable? This is a show stopper as the 1v1 rail is required for the power delivery contract communication between the logic board and the external power adapter.

Please confirm.

If yes, remove all power. Meter in diode mode.

Red lead (yes Red) to ground.
Black lead to the LDO pins of each CD3215. Post the diode mode readings.

Your cd3215 or local parts (caps) may be damaged.

After the above, check the resistance to ground of the same PP1V1_UPC_XB_LDO_BMC rail. We are checking to see if there is a shorted cap on this rail.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

PP1V1_UPC_XB_LDO_BMC - 0V

Do you see this on each USB type c port? Even if you flip the power cable? This is a show stopper as the 1v1 rail is required for the power delivery contract communication between the logic board and the external power adapter.

Please confirm.

If yes, remove all power. Meter in diode mode.

Red lead (yes Red) to ground.
Black lead to the LDO pins of each CD3215. Post the diode mode readings.

Your cd3215 or local parts (caps) may be damaged.

After the above, check the resistance to ground of the same PP1V1_UPC_XB_LDO_BMC rail. We are checking to see if there is a shorted cap on this rail.

Yes, they are all 0V.

Diode mode readings & resistances to ground
PP1V1_UPC_TB_LDO_BMC - .527V - 190Kohms to ground
PP1V1_UPC_TA_LDO_BMC - .54V - 190Kohms
PP1V1_UPC_XA_LDO_BMC - .5V - 190Kohms
PP1V1_UPC_XB_LDO_BMC - .527V - 190Kohms

i measured resistance to ground with black probe on ground, but for the diode mode readings i put the red probe on ground

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

From @Piernov's article:

Without communication with the TBT ROM, the 1.1V BMC LDO (PIN 35) won't come up while other LDOs will be present. The 1.1V BMC LDO is used to drive the logic negotiating USB-PD (USB 2.0 communications to charger). When that happens, when USB-C is connected to this CD3215, it will not negotiate 20V and get stuck on 5V, not cycling.

Can you review the voltages on the SPI lines that is showing the CD3215 controllers? This local SPI flash memory holds the firmware for the type c controllers (cd3215).

Post the voltages on each SPI flash pin. The contents of the flash device itself maybe corrupt but start with the voltage check. The dumps for the spi flash (TBT ROM) are available on this forum.

Update:

Also interested in the diode readings of each CC1 & CC2 lines of each cd3215 controller.

The CCx lines are used to communicate with the external type C power delivery adapter.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

From @Piernov's article:



Can you review the voltages on the SPI lines that is showing the CD3215 controllers? This local SPI flash memory holds the firmware for the type c controllers (cd3215).

Post the voltages on each SPI flash pin. The contents of the flash device itself maybe corrupt but start with the voltage check. The dumps for the spi flash (TBT ROM) are available on this forum.

Update:

Also interested in the diode readings of each CC1 & CC2 lines of each cd3215 controller.

The CCx lines are used to communicate with the external type C power delivery adapter.

For UB090
TBT_X_SPI_CLK = 2mV
TBT_T_SPI_CS_L = 3.3V
TBT_T_ROM_WP_L = 3.3V
TBT_T_SPI_MOSI = ~10mv, but I think thats fine, right?
TBT_T_SPI_MISO = 3.3V
PP3V3_UPC_TA_LDO = 3.3V
TBT_T_ROM_HOLD_L = 3.3V

For U2890
PP3V3_UPC_XB_LDO = 3.3V
TBT_X_ROM_HOLD_L = 3.3V
TBT_X_SPI_CLK = .6mV
TBT_X_SPI_MOSI = 10mv - PS I dont have an oscilloscope and measured this value with a multimeter, so I don't know how or if this signal is changing over time
TBT_X_SPI_MISO = 3.3V
TBT_X_SPI_CS_L = 3.3V
TBT_X_ROM_WP_L = 3.3V

and i did red probe on ground again like last time

USBC_TA_CC1 = .54V
USBC_TA_CC2 = .571V
USBC_TB_CC1 = .57V
USBC_TB_CC2 = .57V

USBC_XB_CC1 = .56V
USBC_XB_CC2 = .54V
USBC_XA_CC1 = .54V
USBC_XA_CC2 = .57V

Hope I did these right

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

Remove all power. Meter in lowest resistance mode.

Confirm the resistance of the following parts ?

RB280
RB284

R3095
R3090

From Louis' forum...

Post 3V3_G3H and R7020 voltages.
Also check TBA_AUX_DET, TBA_VDDA/P, SMC_RESET_L and BUF_SMC_RESET_L.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

Remove all power. Meter in lowest resistance mode.

Confirm the resistance of the following parts ?

RB280
RB284

R3095
R3090

From Louis' forum...

RB280, RB284, R3095, and R3090 are all 15 ohms
Theres no TBA_AUX_DET, but there is CHGR_AUX_DET, which is at a stable 1.078V
CHGR_VDDP is 5V
CHGR_VDDA is also 5V

Also SMC_RESET_L and BUF_SMC_RESET_L do not exist on the boardview

[mon2]

Re: MBP A1989 No Power 5.1V .025-.03MA

1) Confirm the resistance of R7015 and also of R7016.

The voltage value of CHGR_AUX_DET is off a bit. Perhaps your meter ?

2) According to the logiwiki for 20V topic, step # 2 notes that the CD3215 have to supply the 1v1 @ LDO_BMC (pin E1 of the BGA package). Your logic board does not have this voltage on either CD3215 ACE controller.

Do you have a flash chip programmer ? May be practical to reflash the contents of the TBT rom device with the factory contents.

You are after the 820-00850 TBT ROM dump:

https://www.badcaps.net/forum/showthread.php?t=104860

See the post from @willisk.

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

RB280, RB284, R3095, and R3090 are all 15 ohms
Theres no TBA_AUX_DET, but there is CHGR_AUX_DET, which is at a stable 1.078V
CHGR_VDDP is 5V
CHGR_VDDA is also 5V

Also SMC_RESET_L and BUF_SMC_RESET_L do not exist on the boardview

Update: There appears to be a NC_CHGR_SMC_RST_L, but there is no point on the board for me to test it. When I use the boardview the only contact is directly on the ISL9240 somehow

I assume SMC_RESET_L is what this line was denoted as on older boards

:/

[SugamaGoc]

Re: MBP A1989 No Power 5.1V .025-.03MA

1) Confirm the resistance of R7015 and also of R7016.

The voltage value of CHGR_AUX_DET is off a bit. Perhaps your meter ?

2) According to the logiwiki for 20V topic, step # 2 notes that the CD3215 have to supply the 1v1 @ LDO_BMC (pin E1 of the BGA package). Your logic board does not have this voltage on either CD3215 ACE controller.

Do you have a flash chip programmer ? May be practical to reflash the contents of the TBT rom device with the factory contents.

You are after the 820-00850 TBT ROM dump:

https://www.badcaps.net/forum/showthread.php?t=104860

See the post from @willisk.

I double checked CHGR_AUX_DET and the value is still 1.07V, but R7015 is reading really low at 220kOhm and R7016 is reading at around 200kOhm

I do have a raspberry pi that I use as a flash chip programmer