Macbook Pro A1706 doesn't power on

[miro.manchev]

Hi, my own laptop died. One morning it doesn't start up. No charging, nothing. I've opened it, found the boardview and schematic, here in the forum. So I was able to trace some power lines.

I know about the Enable power line for USB-C chips so my PP3V3_G3H is 3.3V and seems fine. Then I saw that PPBUS_G3H is very low, about 0,51V. After some tracing on the board, I found short on PP3V3_UPC_XB_LDO, which is near one of the CD3215C00. Firstly I saw a ceramic cap ( C3208), that looked a bit blackish, so I've unsolder it, but the short remained. So, do you think if I replace CD3215C00 it may work? it's U3200 on the schematic I believe.

Thanks

[piernov]

Re: Macbook Pro A1706 doesn't power on

Did you check voltage&current on USB-C ammeter? I guess you have 5V on DC-in?

There's still C2890 and U2890 on PP3V3_UPC_XB_LDO, very unlikely to be the problem but still confirm they are not causing the short.
It looks like your CD3215C00 are underfilled so they'll be a pain to remove and replace. If you don't have experience with underfilled BGA chips I'd recommend having someone who does have experience do the job. Or at the very least practice on donor boards beforehand.

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

Did you check voltage&current on USB-C ammeter? I guess you have 5V on DC-in?

There's still C2890 and U2890 on PP3V3_UPC_XB_LDO, very unlikely to be the problem but still confirm they are not causing the short.
It looks like your CD3215C00 are underfilled so they'll be a pain to remove and replace. If you don't have experience with underfilled BGA chips I'd recommend having someone who does have experience do the job. Or at the very least practice on donor boards beforehand.

Unfortunatelly I don't have an USB-C volt and ampermeter. I've ordered one, but I couldn't wait it to arrive, so I used only my multimeter. The CD3215 look like glued or something, and my idea was to bring it to someone experienced in BGA soldering, I cannot risk ruin the board, as my data is still there I put an image showing clearer the chip's base.

[Weelcup]

Re: Macbook Pro A1706 doesn't power on

You can clean it with isopropyl alcohol 99% not white spirit.
And see.

Was there any waterdamage ?

[piernov]

Re: Macbook Pro A1706 doesn't power on

There's no sign of liquid damage, LDI are not triggered and CD3215 themselves won't get directly damaged by liquid since they are underfilled. So I assume no liquid damage.
A knockoff AC adapter could've been the cause of it dying, but sometimes it can die randomly too.

Since this is not a T2 Macbook, the data itself can still be rescued from the Lifeboat connector. If you really worry about losing data, you should find someone with the equipment to hook up to that connector and save the data before working on the board. And always make frequent backups.

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

There is no liquid damage, and I never used a knockoff adapter. I have 2 genuine Apple AC adapter, but one of the USB-C cables started to make bad contact, not sure if that can cause the chip burn out. I have some backup's, so I can try to save the board, and even something happens, nothing major will be lost.

P.S. I took a closer look and I'm not sure that this BGA is underfiled. I cannot see epoxy on the edges.

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

The CD3215 finally arrived and I gave it to a workshop to reball it. It was replaced, but the laptop is still dead. The short on PP3V3_UPC_XB_LDO is gone and there is 3.3V now there.

I saw that the PPBUS_G3H is not present, but it's not shorted. It behaves strangely, varies from 750k to ~ 400k but while measuring it's dropping instead of rising. So I focused on D6902 diode.

D6902 diode pinout:
- 1. PPBUS_G3H 300mV 400-750kOhm
- 2. PPDCIN_G3H_CHGR 5.2V
-3. PPVIN_G3H_P3V3G3H 4.8V

The laptop is consuming 5.20V and about 0.03-0.05A on the USB meter.

I measured the double diode, and seems fine 0,5V on the anodes while measuring diode on the multimeter, and 0 if I change the polarity of the probes.

I'm really stuck now, and have no idea what to check now? Any help will be apreciated.

Regards

[piernov]

Re: Macbook Pro A1706 doesn't power on

R6907 is the resistor that feeds the PP3V3_G3H regulator circuit when on battery. It is not relevant here, PP3V3_G3H will be fed directly from the AC adapter through R6902.

If the ammeter is still stuck at 5V, you have to check the voltage on PP3V3_G3H again and all the LDO outputs of all the CD3215C00.

[Weelcup]

Re: Macbook Pro A1706 doesn't power on

The CD3215 finally arrived and I gave it to a workshop to reball it. It was replaced, but the laptop is still dead. The short on PP3V3_UPC_XB_LDO is gone and there is 3.3V now there.

I saw that the PPBUS_G3H is not present, but it's not shorted. It behaves strangely, varies from 750k to ~ 400k but while measuring it's dropping instead of rising. So I focused on D6902 diode.

D6902 diode pinout:
- 1. PPBUS_G3H 300mV 400-750kOhm
- 2. PPDCIN_G3H_CHGR 5.2V
-3. PPVIN_G3H_P3V3G3H 4.8V

The laptop is consuming 5.20V and about 0.03-0.05A on the USB meter.

I measured the double diode, and seems fine 0,5V on the anodes while measuring diode on the multimeter, and 0 if I change the polarity of the probes.

I'm really stuck now, and have no idea what to check now? Any help will be apreciated.

Regards

Did you disconnect the battery and get this 5v on the metre? If so then i would still suspect the usbc chip (the CD3215 chip) circuit.

Check the 1M ohm resistors on around all the CD3215 chips.
In general, check all CD3215 feeding resistors values. I would suspect a defected resistor as the value on the metre should be 20v.



However, it is very very important to use a high wattage 87w like usbc charger before you go with anything else. Very possible charger defect (adapter or cable) issue might lead to 5v instead of 20v

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

I have 3 original 61W usb-c apple chargers. I have another macbook pro and I verified they are working well, and also tested the usb-c meter working fine. The battery is disconnected and never put back while diagnostic work. I bought the CD3215C00 from ebay, so I can suspect bad chip, or bad reflow work as I cannot be 100% sure it was done properly. But the short is gone and there is 3.3V there now. As I can see from this power rail name PPVIN_G3H_P3V3G3H
isn't 4.8V voltage too high?
Will a new CD3215C00 work right a way, without any needs of coding?

I will check all resistors and LDO outputs on all CD3215C00.

Regards

[piernov]

Re: Macbook Pro A1706 doesn't power on

PPVIN_G3H_P3V3G3H is the input voltage for PP3V3_G3H regulator as the name suggests. Voltage is brought down to 3.3V by the regulator so PP3V3_G3H should mesure 3.3V.
CD3215C00 are custom chips pre-programmed for Apple, they most likely are not "new" but rather pulled from donor boards. As long as the revision C00 matches with all the other chips it's good.

[Weelcup]

Re: Macbook Pro A1706 doesn't power on

I have 3 original 61W usb-c apple chargers. I have another macbook pro and I verified they are working well, and also tested the usb-c meter working fine. The battery is disconnected and never put back while diagnostic work. I bought the CD3215C00 from ebay, so I can suspect bad chip, or bad reflow work as I cannot be 100% sure it was done properly. But the short is gone and there is 3.3V there now. As I can see from this power rail name PPVIN_G3H_P3V3G3H
isn't 4.8V voltage too high?
Will a new CD3215C00 work right a way, without any needs of coding?

I will check all resistors and LDO outputs on all CD3215C00.

Regards

Great!,
As much as you guarantee the charger itself then we passed it.

Now, just to be clear. If a SINGLE CD3215 on the board is defective, NONE OF THE OTHERS WILL WORK!
I mean all would show 5v on metre when you connect the charger to.

So try to see if the G3H_P3V3G3H 3.3v is present when you connect the charger to the other usbc ports one by one.
However, do should do resistors checks that mentioned before.. make sure the 1M ohms are not reading higher resistance...

For now ignore the PPVIN 4.8v.

Also check if the metre is reading higher amps when connected to the other ports.

Like "piernov" mentioned this exact model chip is pre programmed and if not working then it is highly likely defected or bad soldering.

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

There are some strange things going on. The usb-c meter recognize 5V only from one of the sides, and on one of the usb-c there is interupts after about 10s, goes to 0V and then again 5.2V. On the second port it works without flickering. The other side stays dead. I'm pretty sure it was working too, before I put the mother board inside the laptop. There are no other ribbon cables connected, just the USBs. I will put the board out againg and check, if I there is some bad connection to this side ports. P3V3_G3H is present and it's 3.3-3.4V. The 1mOhm resitors are between 650k-800k, I've check the others near CD3215C00, some 15k and 2,2k and looks fine on the multimeter.

[Weelcup]

Re: Macbook Pro A1706 doesn't power on

There are some strange things going on. The usb-c meter recognize 5V only from one of the sides, and on one of the usb-c there is interupts after about 10s, goes to 0V and then again 5.2V. On the second port it works without flickering. The other side stays dead. I'm pretty sure it was working too, before I put the mother board inside the laptop. There are no other ribbon cables connected, just the USBs. I will put the board out againg and check, if I there is some bad connection to this side ports. P3V3_G3H is present and it's 3.3-3.4V. The 1mOhm resitors are between 650k-800k, I've check the others near CD3215C00, some 15k and 2,2k and looks fine on the multimeter.

If all the resistors are ok. Then one of the CD3215's is faulty. lt might be the one that is cutting the power that you just mentioned..

...

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

Any idea from where to source a good CD3215C00? I bought one from ebay, but I cannot be sure it was ok. However, the one cutting the power is different from the one that was changed.

[Weelcup]

Re: Macbook Pro A1706 doesn't power on

Any idea from where to source a good CD3215C00? I bought one from ebay, but I cannot be sure it was ok. However, the one cutting the power is different from the one that was changed.

As mentioned above, it is very unlikely to find new ones. And any one online would have been taken from donor boards.

However, i personally order such chips from ebay too but from a chinese source.. i had not have any issues with any chip that i ordered from so far ( since 2017 ).

https://www.ebay.com/itm/202621291250

But it might take some time to get it delivered during this pandemic period.

[philipjhart]

Re: Macbook Pro A1706 doesn't power on

I've opened it, found the boardview and schematic, here in the forum. So I was able to trace some power lines.

Do you have a link to the forum where you found the board view & schematic?

Newbie here, so still trying to figure how BadCaps works!

Cheers,
Philip

[Weelcup]

Re: Macbook Pro A1706 doesn't power on

Do you have a link to the forum where you found the board view & schematic?

Newbie here, so still trying to figure how BadCaps works!

Cheers,
Philip

You can find it here.
This is for A1706 touchbar model.
820-00239-A

https://www.badcaps.net/forum/showthread.php?t=63867

Goodluck.

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

This is a video how the 4 USB-C behave. Only one is not boot looping, and the rest are. However, the one that doesn't boot loo, at some point the Amparage drops to 0 and then rises again to 40-50mA, looping in it's own way. I'm not sure what to meassure now, and how much CD3215 to order and replace...

https://www.youtube.com/watch?v=ONSX6iLbgIY

[miro.manchev]

Re: Macbook Pro A1706 doesn't power on

Could it be something with thunderbolt RAMs ?