Macbook Pro 13 820-00840 PP3V3_G3H Problem

[MobileXT]

I'm working on a Macbook Pro 13 820-00840 that no physical water damage the macbook is clean. The problem was missing PP3V3_G3H power rail I replaced ISL9239 and U6990 and now stuck at 2.2v on PP3V3-G3H power rail I replaced all the component for the PP3V3_G3H Power rail and still have the same results. I replaced the U6990 5 times and still stuck @ 2.2V no short to ground. any idea what was wrong on this machine. Thanks

[mon2]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

What is the input voltage to the regulator isl9239?

Meter in resistance mode. What is the resistance to ground for the PP3V3_G3H rail ?

Check the feedback resistors for the isl9239. Do not power on without these feedback resistors but confirm their values.

See attached.

1) what is the voltage reading @ L6995, pin # 2 ? This should be about 3v4 here.

2) If the voltage here is not correct then remove all power.

Meter in resistance mode. Check and post the resistance to ground of L6995, pin # 2. We are checking for a bad cap / solder that may be tanking this rail.

Post the resistance value.

3) Next, if the voltage is not correct, consider to remove the shorting resistor @ R6999. With the resistor removed, what is the voltage @ L6995, pin # 2 ?

Is it the expected 3v4 / 3v42 ?

If not, then check and post the voltage @ D6905, pin # 3.

[MobileXT]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

What is the input voltage to the regulator isl9239?

Meter in resistance mode. What is the resistance to ground for the PP3V3_G3H rail ? .344V on a diode mode Resistance;3.366 K ohms

Check the feedback resistors for the isl9239. Do not power on without these feedback resistors but confirm their values.

See attached.

1) what is the voltage reading @ L6995, pin # 2 ? This should be about 3v4 here. I only have 2.2V

2) If the voltage here is not correct then remove all power.

Meter in resistance mode. Check and post the resistance to ground of L6995, pin # 2(. We are checking for a bad cap / solder that may be tanking this rail.

Post the resistance value.

3) Next, if the voltage is not correct, consider to remove the shorting resistor @ R6999. With the resistor removed, what is the voltage @ L6995, pin # 2 ?

Is it the expected 3v4 / 3v42 ? I only getting 2.2v

If not, then check and post the voltage @ D6905, pin # 3 (3.9V) .

I replaced all the components for PP3V3_G3H still only get 2.2.V

[mon2]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

There was no reason to replace each of the parts. Not yet till we know more.

What are the voltage values @ pins 1 and 2 of D6905. The voltage being fed into this local regulator is not high enough.

The voltage on one side of the diode should be much higher and match close to the DCIN adapter voltage.

The other input pin to this diode should be equal to the battery voltage. If the battery is not connected, then this voltage should be 0V which is fine.

At this time, you can remove D6905 to confirm the input voltages for this component. Is the voltage on pin # 1 of the D6905 much higher with D6905 removed ?

[MobileXT]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

If I removed R6999 I have 3.3V. at DIODe mode PIN2 at r6999 I have .339v

[mon2]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

The voltage going into this voltage regulator is too low if you are reading 3v9.

The voltage is fed from pin #3 of the dual diode @ D6905. At least one of the inputs into this dual diode must be much higher.

Meter in DC volts mode. What is the voltage on pin #1 of D6905 with your power adapter connected ?

I think your PPBUS_G3H is not the proper value out of the ISL9239.

1) What is the voltage @ F7000, pin # 2 ? F7000, pin # 1 ?

2) What is the voltage of PPDCIN_G3H ? This is the rail that enters the ISL9239 to create PPBUS_G3H.

[MobileXT]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

The voltage going into this voltage regulator is too low if you are reading 3v9.

The voltage is fed from pin #3 of the dual diode @ D6905. At least one of the inputs into this dual diode must be much higher.

Meter in DC volts mode. What is the voltage on pin #1 of D6905 with your power adapter connected ?

I think your PPBUS_G3H is not the proper value out of the ISL9239.

1) What is the voltage @ F7000, pin # 2 ? F7000, pin # 1 ?

2) What is the voltage of PPDCIN_G3H ? This is the rail that enters the ISL9239 to create PPBUS_G3H.

D6905 PIN1= 0V, PIN2=5.20v PIN3=3.966v with the power adapter connected only.

voltage on F007= PIN1= 0.063V PIN2=0.063V

PPDCIN_G3H= 5.18V

[mon2]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

Remove all power.

Meter in resistance mode (200 ohms).

Measure and post the resistance to ground of

1) D6905, pin #3.
2) F7000, pin #2.

Next check the resistance across fuse F7000. Value?

[MobileXT]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

remove all power.

Meter in resistance mode (200 ohms).

Measure and post the resistance to ground of

1) d6905, pin #3. 3.65㏁
2) f7000, pin #2. 4.48㏁

next check the resistance across fuse f7000. Value?

0.6Ω

[mon2]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

1) Fuse is ok.

2) Does not appear that you have a short on the tested rails.

3) Remove D6905 from the logic board - it is a SOT-23 device.

After it is removed off the board, meter in diode mode.

Check this dual diode out of circuit.

Place the red meter lead on pin #1 and black on pin # 3. What is the reading?
Place the red meter lead on pin #2 and black on pin # 3. What is the reading?

Then reverse the leads and check again.

Place the black meter lead on pin #1 and red on pin # 3. What is the reading?
Place the black meter lead on pin #2 and red on pin # 3. What is the reading?

[MobileXT]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

1) Fuse is ok.

2) Does not appear that you have a short on the tested rails.

3) Remove D6905 from the logic board - it is a SOT-23 device.

After it is removed off the board, meter in diode mode.

Check this dual diode out of circuit.

Place the red meter lead on pin #1 and black on pin # 3. What is the reading?
Place the red meter lead on pin #2 and black on pin # 3. What is the reading?

Then reverse the leads and check again.

Place the black meter lead on pin #1 and red on pin # 3. What is the reading?
Place the black meter lead on pin #2 and red on pin # 3. What is the reading?

Thanks mon2 the diode is the problem the donor board diode is also a bad one. Now I replaced with a working one its chimes.... Thanks man2 for your help.

[Steven Pieter]

Re: Macbook Pro 13 820-00840 PP3V3_G3H Problem

What is the input voltage to the regulator isl9239?

Meter in resistance mode. What is the resistance to ground for the PP3V3_G3H rail ?

Check the feedback resistors for the isl9239. Do not power on without these feedback resistors but confirm their values.

See attached.

1) what is the voltage reading @ L6995, pin # 2 ? This should be about 3v4 here.

2) If the voltage here is not correct then remove all power.

Meter in resistance mode. Check and post the resistance to ground of L6995, pin # 2. We are checking for a bad cap / solder that may be tanking this rail.

Post the resistance value.

3) Next, if the voltage is not correct, consider to remove the shorting resistor @ R6999. With the resistor removed, what is the voltage @ L6995, pin # 2 ?

Is it the expected 3v4 / 3v42 ?

If not, then check and post the voltage @ D6905, pin # 3.

hello mon2 sorry for distrub your time may i ask you? i have same problem with my macbook pro a1706 which is have lower pp3v3 it only showing 2V. I have been trying to. remove R6999 which is susccesfull i got around 3v more on the L6995 pin #2. The mac only takes 5.13V and 0.30A while charging. notes: sorry with my bad english spealing im not really familier with english. Thank you for the help

[mon2]

Steven Pieter - can you check the referenced part numbers. Unable to locate them in my schematics for the A1706.

Update - found the references but on 820-00840 (A1708 schematic).

What is the voltage to ground of:

SMBUS_SMC_5_G3_SCL
SMBUS_SMC_5_G3_SDA

PPBUS_G3H ; check both sides of fuse @ F7000.

If your PP3V3_G3H is low, then the logic board will stop working. Is this the rail showing 2 volts?

Anytime you have a lower than expected voltage rail, power down / remove all sources of power including battery - meter in resistance mode -> measure the resistance to ground of the faulty power rail.

So for your case, measure the resistance to ground of PP3V3_G3H @ L6995 (either side is ok).

Respectively, do inspect the dual common cathode diode @ D6905. Often, this wimpy dual diode is the root cause. Carefully, measure the voltage to ground of each side of this diode.

The voltage @ pin # 3 should only be ~ 0v6 LOWER than the input voltage fed @ pin # 1 or pin # 2 of this dual diode. This dual diode will select the higher of the 2 input voltages - that is, either the power adapter or battery as the source to power this critical power rail.

From history, the caps @ C6990 / C6991 become shorted and cause an issue here. You can check the resistance to ground (without power to the board) on pin # 3 of this diode to confirm either way.

Update:

1) Yes, remove R6999 if the resistance is low on this consumer side of the power rail. Then power up again. Do you now have the correct voltage on the PCB pads for this removed resistor ? (pin # 1 - which is facing the producer side = U6990).

2) The above must be stable to move forward.

Post all your updates - need to do some mandatory gardening as not lower my property value. BBL.

[Steven Pieter]

Steven Pieter - can you check the referenced part numbers. Unable to locate them in my schematics for the A1706.

Update - found the references but on 820-00840 (A1708 schematic).

What is the voltage to ground of:

SMBUS_SMC_5_G3_SCL
SMBUS_SMC_5_G3_SDA

PPBUS_G3H ; check both sides of fuse @ F7000.

If your PP3V3_G3H is low, then the logic board will stop working. Is this the rail showing 2 volts?

Anytime you have a lower than expected voltage rail, power down / remove all sources of power including battery - meter in resistance mode -> measure the resistance to ground of the faulty power rail.

So for your case, measure the resistance to ground of PP3V3_G3H @ L6995 (either side is ok).

Respectively, do inspect the dual common cathode diode @ D6905. Often, this wimpy dual diode is the root cause. Carefully, measure the voltage to ground of each side of this diode.

The voltage @ pin # 3 should only be ~ 0v6 LOWER than the input voltage fed @ pin # 1 or pin # 2 of this dual diode. This dual diode will select the higher of the 2 input voltages - that is, either the power adapter or battery as the source to power this critical power rail.

From history, the caps @ C6990 / C6991 become shorted and cause an issue here. You can check the resistance to ground (without power to the board) on pin # 3 of this diode to confirm either way.

Update:

1) Yes, remove R6999 if the resistance is low on this consumer side of the power rail. Then power up again. Do you now have the correct voltage on the PCB pads for this removed resistor ? (pin # 1 - which is facing the producer side = U6990).

2) The above must be stable to move forward.

Post all your updates - need to do some mandatory gardening as not lower my property value. BBL.

First off all thank you for replying, i. have tested SMBUS_SMC_5_G3_SCL, and SMBUS_SMC_5_G3_SDA both side are 0v with the r6999 still removed
on R6999 PP3V3_G3H_REG_R pin #1 3,46V and PP3V3_G3H pin #2 show. 0v
Measure resistance to ground of PP3V3_G3H using diode mode i got 350 ohm with the red prob on ground and black prob on PP3V3_G3H
Measure diode D6905 pin #1 (PPBUS_G3H_R) i get 464 ohm, on pin #2 (PPDCIN_G3H_CHGR_R) 595 ohm, and on the pin #3 (PPVIN_G3H_P3V3G3H) i get 590 ohm
Measure voltage on D6905 pin #1 i get 1,12v but it keep dropping each second and it stay on 0.66v (no battery installed), on pin #2 i. get 5.30v, and pin #3 i get 5.17v

1. Remove R6999, yes i have 3.46v

[mon2]

Man I hate gardening....

1. Remove R6999, yes i have 3.46v

Good. This confirms the input voltage is ok and that the dual diode @ D6905 is passing through ample voltage to create this desired voltage output.

With NO power to the board, measure the resistance (not diode mode) to ground on the removed R6999, PCB pad # 2. This is the opposite side to where you measured the 3v46. We are checking the resistance on the downstream (aka consumer side) to understand if there is an excessive load on this wimpy rail. This regulator can only support ~300 mA and anything excessive will cause the rail to become 0 or at least lower.

Post the resistance in ohms to ground.

[Steven Pieter]

Man I hate gardening....


Good. This confirms the input voltage is ok and that the dual diode @ D6905 is passing through ample voltage to create this desired voltage output.

With NO power to the board, measure the resistance (not diode mode) to ground on the removed R6999, PCB pad # 2. This is the opposite side to where you measured the 3v46. We are checking the resistance on the downstream (aka consumer side) to understand if there is an excessive load on this wimpy rail. This regulator can only support ~300 mA and anything excessive will cause the rail to become 0 or at least lower.

Post the resistance in ohms to ground.

im sorry but are this the correct way to check the resistance on pin #2 R6999 i put the black prob on the ground and red one on the pcb pad #2. After that i set my multimeter on 200 ohm? I'm sorry because I'm not someone who really understands electronics, I'm just learning to understand it. and sorry, I only use Google Translate as a communication medium so the language is not very good. Thank You

[Steven Pieter]

Man I hate gardening....


Good. This confirms the input voltage is ok and that the dual diode @ D6905 is passing through ample voltage to create this desired voltage output.

With NO power to the board, measure the resistance (not diode mode) to ground on the removed R6999, PCB pad # 2. This is the opposite side to where you measured the 3v46. We are checking the resistance on the downstream (aka consumer side) to understand if there is an excessive load on this wimpy rail. This regulator can only support ~300 mA and anything excessive will cause the rail to become 0 or at least lower.

Post the resistance in ohms to ground.

hello mon2 i got some news, when i trying to inject voltage on pin #2 R6999 i saw that U3100 heating up and before i test to inject the voltage there are one usb port that does work on that ways. If i change the ic i will get change to repair this mac? Thank you

[mon2]

What is the voltage of your USB Type C meter when using the port linked to U3100? Only if all ACE controllers (including U3100) are working will the type C meter negotiate to 20V operation.

If this part is heating up then yes, recommend to replace this part. Be sure the source part is reliable or taken from a known good donor board and reballed.

[Steven Pieter]

What is the voltage of your USB Type C meter when using the port linked to U3100? Only if all ACE controllers (including U3100) are working will the type C meter negotiate to 20V operation.

If this part is heating up then yes, recommend to replace this part. Be sure the source part is reliable or taken from a known good donor board and reballed.

thank you for replying mon2 when i plug the charger to mac i only got 5v11 and 0.29A with the first usb c port, if i use the second one the usb tester doest show and boot as it should.

[mon2]

To confirm, this is the 2nd USB port in your testing? From the article on how 20V is selected, all CD321x ACE (power delivery) controllers must be operational to allow for the 20 volts to be selected.

reference reading:

CD3215 Bootup Sequence - LogiWiki