MacBook Pro A1706 - Stuck at 5V and 0.09A

[BMCappelletti]

Hi everyone.
MacBook Pro, model A1706, EMC 3071. Charger shows only 5V and only 0.09A drawn. Board is 820-0239-A. Mint condition. Pretty sure no one ever opened it and was not used much.
I tested all steps from the table here https://logi.wiki/index.php/CD3215_Bootup_Sequence changing the CD3215 lines as I moved from one USB-C to the other.
What I found was:
- on step 3, I have the voltages as 10V and 7.8V, indicated as "Air" on this table, which I suppose would be for a MacBook Air. But this one is a Pro. Same on all DC3215s.
- on step 11, on diode mode, I have 0.47V to 0.48V, not the 0.8V. Again, for all DC3215s.
- the ones marked as 20V there is no reason to test, as the board does not pull 20V from the charger. But I do have 5V in them.
- step 15 says 5V on TBA_AUX_DET. I have 1.3V.

The schematic for this board shows this.



The board does not have that C7016 cap, but has the resistors. They are hard to measure, as are really small. And I know I should remove them from the board. But, on circuit, R7016 is measuring 150k ohms and R7015 is measuring 1.3M ohms.
Any help on what I should try or measure next is much appreciated.
Thank you.

[mon2]

Do not remove any parts till more is known about the logic board's condition.

What is the voltage to ground of PPBUS_G3H @ fuse F7000 ? Check each side.

[BMCappelletti]

Do not remove any parts till more is known about the logic board's condition.

What is the voltage to ground of PPBUS_G3H @ fuse F7000 ? Check each side.

13V on both sides.

[mon2]

13v is a good voltage to ground reading.

- on step 11, on diode mode, I have 0.47V to 0.48V, not the 0.8V.

Step 11 is a voltage to ground reading - not a diode mode measurement.

Do you have each of the LDO voltage readings to ground for the active CD3215 ACE controller? Do they match the referenced article on CD3215 boot sequence?

What is the voltage to ground of PP3V3_G3H @ L6900 ?


Review this webpage:

https://repair.wiki/w/MacBook_Pro_A1..._of_20V_repair

[BMCappelletti]

13v is a good voltage to ground reading.



Step 11 is a voltage to ground reading - not a diode mode measurement.

Do you have each of the LDO voltage readings to ground for the active CD3215 ACE controller? Do they match the referenced article on CD3215 boot sequence?

What is the voltage to ground of PP3V3_G3H @ L6900 ?


Review this webpage:

https://repair.wiki/w/MacBook_Pro_A1..._of_20V_repair

Yes, I do have the LDO voltages. They are all equal the ones from that table.
Voltage on L6900 is 3.4V.

The link you sent seems to be all around PP3V3_G3H, which I do have. I can't see any corroded componentes, from the ones mentioned in there. The board is really clean.

Checked CC1 and CC2 again. I do have 0.8V on it. Small components. Has a bad measure before.

[mon2]

The CC1 / CC2 lines are the single wire BMC interface lines. Each is used by the host logic board and the external power adapter to select the power delivery contracts. Respectively, the LDO must be operational on that CD3215 being tested to power this leg of the circuit. Note - you will only measure a voltage on the CC1 / CC2 pin if that side of the type C blade and that type C connector is in use. That is, you may measure something on CC1 but nothing on CC2 till you rotate the power adapter type C connector. Then the CC pins will reverse. It is the CCx pins that become active during the respective orientation of the cable head.

Believe it is the 1v0 LDO rail used for the BMC interface but you can confirm by checking the netnames in the schematic. Respectively, the 5v power delivery contract is the factory default of all power delivery capable power adapters. After a proper communication over the CCx line, a higher pair of voltage / current contract will be selected (ie. 20V @ 5A, etc.).

Do check the condition of the SPI flash devices which are used as the firmware for the CD321x devices.

[BMCappelletti]

The CC1 / CC2 lines are the single wire BMC interface lines. Each is used by the host logic board and the external power adapter to select the power delivery contracts. Respectively, the LDO must be operational on that CD3215 being tested to power this leg of the circuit. Note - you will only measure a voltage on the CC1 / CC2 pin if that side of the type C blade and that type C connector is in use. That is, you may measure something on CC1 but nothing on CC2 till you rotate the power adapter type C connector. Then the CC pins will reverse. It is the CCx pins that become active during the respective orientation of the cable head.

Believe it is the 1v0 LDO rail used for the BMC interface but you can confirm by checking the netnames in the schematic. Respectively, the 5v power delivery contract is the factory default of all power delivery capable power adapters. After a proper communication over the CCx line, a higher pair of voltage / current contract will be selected (ie. 20V @ 5A, etc.).

Do check the condition of the SPI flash devices which are used as the firmware for the CD321x devices.

Yep. I had to rotate the charger connector to get some readings.

As for LDOs... you mean PP1V1_UPC_XB_LDO_BMC? I do have 1.1V on it, on 4 measurements (each CD3215).

By SPI flash you mean the MXIC EFI chip? All seems fine. Receiving 3.3V. CD3215 firmware would be the TB ROM chip? Visually fine, too. And getting 3.3V.

Sorry if I missunderstood something.

[BMCappelletti]

Ok. Reading again your message. You meant only the thunderbolt part. Ok. Same answer, anyway.

[mon2]

Yes, ok not BMC CCx pins.

Is your logic board power cycling or just climbs to this low current draw of 90mA and stops?

[BMCappelletti]

Yes, ok not BMC CCx pins.

Is your logic board power cycling or just climbs to this low current draw of 90mA and stops?

Climbs and stops. No power cylcing. So I guess there is no issue with a specific CD3215, but with something else.

[mon2]

What is the voltage to ground of PP3V3_UPC_TA_LDO ? PP3V3_UPC_XB_LDO ?

Also interested in the voltage to ground values for:

SMBUS_SMC_5_G3_SCL
SMBUS_SMC_5_G3_SDA
* although these should be ok since PPBUS_G3H is @ 13v which means the SMC has boosted this voltage rail already using the same I2C interface


Suggest to remove all power. Meter in resistance mode. Measure the resistance to ground of each inductor on the board. Checking for any low resistance measurement -> then review which power rail is linked to this low resistance to ground inductor.

At this time, the ISL9239, which is a buck/boost regulator is acting in boost voltage mode (5V input -> boosted to 13v output). Would you have a flash IC programmer tool? You can consider to reflash the firmware that resides inside of U2890 and UB090.

[BMCappelletti]

What is the voltage to ground of PP3V3_UPC_TA_LDO ? PP3V3_UPC_XB_LDO ?

Also interested in the voltage to ground values for:

SMBUS_SMC_5_G3_SCL
SMBUS_SMC_5_G3_SDA
* although these should be ok since PPBUS_G3H is @ 13v which means the SMC has boosted this voltage rail already using the same I2C interface


Suggest to remove all power. Meter in resistance mode. Measure the resistance to ground of each inductor on the board. Checking for any low resistance measurement -> then review which power rail is linked to this low resistance to ground inductor.

At this time, the ISL9239, which is a buck/boost regulator is acting in boost voltage mode (5V input -> boosted to 13v output). Would you have a flash IC programmer tool? You can consider to reflash the firmware that resides inside of U2890 and UB090.

PP3V3_UPC_XB_LDO is 3.3V on all CD3215s.
PP3V3_UPC_TA_LDO also 3.3V.

Yes, both SMBUS lines at 3.4V.

I do have a programmer. Not sure if I have any compatible board to solder those componentes on and read it.
I'll check it later. And check the resistances.
Need to do some stuff outside home. Will be back later.
Thanx a lot.

[BMCappelletti]

The only really low resistances found are on the top coils, with 3V, 3V, 3V, 6V, 6V and 9V. But they are all CPU.
The others are:
P1VS4 - 79 ohms
P1V0PCH - 53 ohms
P1V2 - 237 ohms
PVCCIO - 49 ohms
P2V7NAND - 12K ohms
P5VUSBC - 9K ohms
PP5V - 41K ohms
PP3V3 - 34K ohms
TBA - 2,1M ohms
PPVIN - 1,08 ohms
P5VUSBC - 8K ohms

[mon2]

PPVIN - 1,08 ohms

Can you confirm this one?

[BMCappelletti]

Can you confirm this one?

1.08M.

[mon2]

What is the voltage to ground of ALL_SYS_PWRGD ?

[BMCappelletti]

What is the voltage to ground of ALL_SYS_PWRGD ?

I got 0 on it.

[BMCappelletti]

Going ahead of myself cause... why not? I measured all pgood lines.

CPUVR_PGOOD - 0V
P1V0PCH_PGOOD - 3.3V
P1V8SUS_PGOOD - no test point
P1VSUS_PGOOD - 3.3V
P2V7NAND_PGOOD - 0V
P2V7NAND_PGOOD_R - 0V
P3V3SUS_PGOOD - no test point
P5VS4_PGOOD - 3.3V
P5VUSBC_X_PGOOD - 1.2V
PICCOLO_PGOOD - 0V
PVCCIO_PGOOD - no test point

[mon2]

Good. This power good line being low means that at least one of your power rail is not at a good voltage. Review the NAND voltage rail from your above list. Measure the voltage to ground of this power rail.

Next, remove all power -> measure the resistance to ground of this same power rail. Post each measurement.

[BMCappelletti]

Good. This power good line being low means that at least one of your power rail is not at a good voltage. Review the NAND voltage rail from your above list. Measure the voltage to ground of this power rail.

Next, remove all power -> measure the resistance to ground of this same power rail. Post each measurement.

Both P2V7NAND lines are on R9411 resistor. Both show around 12k ohms to ground, with 0V.
P2V7NAND_PGOOD goes to U9300 area.
P2V7NAND_PGOOD_R goes to U9400, right above it.