MacBook Pro 15" 2017 A1707 Touchbar No power

[powerblackout]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

I understand from the repair wiki that if LDO 1.1 is not short and no voltage, it is the CD3215.

The one I read said lack of 1.1 LDO means it's a ROM issue, try replacing the ROM chip? Can you measure the voltage on your MISO and MOSI lines to the chip?

Here's another thread I found: https://boards.rossmanngroup.com/thr...ldo_bmc.58788/

If we could get a few dumps of good ROMs It would be interesting if this would fix the 1.1v issue..

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

hi, thanks that is a great find! I have no voltage on both pins.
Also no short. I found the chip here:
https://www.ebay.com/itm/312661170913
but I am not sure if I want to invest that.
The chip looks good and no power so perhaps problem is power?
Also interestingly I saw no R4106 is on my board, but it does not look like fallen off.
Chip looks clean too but I have cleaned it before so may indeed be dead.
Then I saw R4104 is missing which should power the SPI rom U3906!

Unfortunately no 1.8V on the incoming track there but I think I should try to fix that first . Some light in the darkness, thanks a lot!
[update] R4104 contacts do not look like something was there either. may be it should not be there?
SOC_ROM_SPI_MISO_R read about 0.09V on pin 2 of R4450.
again no short around there.

How likely is it to be the chip?

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

I watched https://www.youtube.com/watch?v=alhLFikA3g8 after watching the wiki again. Then I understood the ROM is the TB ROM, U2895 not the EFI ROM (SPI?).
That actually looks like it could be my problem.

I do not have a donor board so I will check chip price and post if news. Glad to still be going and learning, even with no reward of a working board, it is rewarding to learn from all of you guys sharing knowledge.
Thanks a lot!

[powerblackout]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Do you have a programmer? I can send you a ROM file off of a working TBT chip and you could try flashing it onto yours.

If you purchase a new chip it's not going to have the firmware the CD3215 chips required to get 20v, you'll need to program it unless you get a used one off of a board.

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Do you have a programmer? I can send you a ROM file off of a working TBT chip and you could try flashing it onto yours.

If you purchase a new chip it's not going to have the firmware the CD3215 chips required to get 20v, you'll need to program it unless you get a used one off of a board.

Hi, yes I do, just not sure if I have the proper connector, but can order that.
Do you mean programming the current chip or a new one?
Do you have a good link for a replacement chip on ebay?

BIOS image is appreciated, found them on Rossman forums but behind paywal.
My board is 820-00281-A.
Thank you!

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

I found : https://www.aliexpress.com/item/1005003614452960.html
My U2890 shows :

*-8029B ( star is unclear, B might be 8 or 9)
300 (or 800 )
MX25
U3235F

If only the last two lines are important I can order that one and try to program.

[powerblackout]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

I just found a donor board that was able to get 20V, swapped the TBT ROM but still had the same issue, so your ROM might be fine.

Do you have an oscilloscope? Push it up against the MISO line going into the CD3215 and plug the board in, if you see a short burst of traffic your ROM is probably fine and your problem elsewhere.

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

A1707 is about power delivery.

Power delivery (PD) lines are the CCx lines on the USB Type C connectors.

Check the diode readings for the:

CCx lines
D+ / D- lines

(Meter in diode mode. Red meter (yes, RED) to ground. Black to point to test).

Most of the boardview files offer DIODE reading values of a known good board. Compare your values against the reference values.

hi, sorry I somehow missed this @mon2 .
here they are :
u3100:
cc1 : 0.59
cc2 : 0.59

u3200
cc1: 0.58
cc2: 0.74

ub300:
cc1: 0.56
cc2: 0.57

ub400:
cc1: 0.56
cc2: 0.57


@powerblackout I have 3.3V on UB2890.
Have an oscilloscope to borrow but never used so would need more instructions.
About missing R41*, those are fine, the do not match the schematics as i saw in the video from Paul Daniels.
CB214 I pit back it should be fine.

Do te diod readings say anything?
Feel free to post that ROM file anyway, can be useful because hard to find.
Can you explain what do to with the oscilloscope?

The ROM chip had some liquid spill so it might actually be that in my case.
Thank you again for the help and support.
For convenience, please find the schematics attached that I am using.
I ordered some chips, they were cheap, I hope they are the rights ones.
I'll try to take this all the way, since I have kind of given up on being able to fix it, so it would be absolutely awesome if we can pull it off anyway

[mon2]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

u3200
cc1: 0.58
cc2: 0.74

U3200 readings are off. Have you replaced this controller? It should be replaced with the same part #.

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

U3200 readings are off. Have you replaced this controller? It should be replaced with the same part #.

Hi,

Thank you, what should the readings be? can´t find it in openboardview.
I replaced it with a new one ( replaced it before but it looked bad )and now it reads 0.53 at both cc points.
Also, it boots with the plug both sides in now - but again to 5.2 V and no rebooting.

More interestingly, UB300 and UB400 side do not go on on any plug orientation now. They used to work both, where one only on one side of USB-c orientation.
The USB power meter I use inline does not go on now on either UB300 or UB400, the diode measurments are the same.

Ideas are welcome, I spend a $100 on CD3215s now, not even sure if supplier chips were good. This is getting very difficult...
I'm kind of done switching CD3215 chips on this board, I get the feeling something may be wrong with it that destroys them, or is that not possible ( or should not)?
Thanks for all the help, hope there is a solution.

[mon2]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Good on the diode reading. From my google-fu experience, the diode readings should be ~0.55 on a good CCx pin.

Earlier, the CC2 reading was much higher so it was a suspect.

Remove all power / no battery.

Meter in DIODE mode.

Red meter probe (yes RED) to GROUND.

Black meter probe on each LDO pin on the CD3215. Measure & post the readings for each CD3215 on the logic board.

On other comments - yes, this is a very frustrating and expensive hobby. In the end, there may be no solution for a fix. It is a man vs. machine challenge. Just the same, the experience is priceless, once it is working. The next round will be much easier to tackle.

[fr.iglesias]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Hi friends, does anyone have the TBT ROM firmware for A1798 820-00875A motherboard?,
I´ll be really gratefull if someone could help me with this.

Thanks in advance!!

[fr.iglesias]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Sorry I mean A1708 motherboard Macbook Pro 13 2016 year

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Good on the diode reading. From my google-fu experience, the diode readings should be ~0.55 on a good CCx pin.

Earlier, the CC2 reading was much higher so it was a suspect.

Remove all power / no battery.

Meter in DIODE mode.

Red meter probe (yes RED) to GROUND.

Black meter probe on each LDO pin on the CD3215. Measure & post the readings for each CD3215 on the logic board.

On other comments - yes, this is a very frustrating and expensive hobby. In the end, there may be no solution for a fix. It is a man vs. machine challenge. Just the same, the experience is priceless, once it is working. The next round will be much easier to tackle.

Thanks for the help and the peptalk !
I have to say I love the learning anyway and to interact with the community like this, so I will try to keep it going .

The readings for LDOs are:
u3100 :
pp1v8_upc_xa_ldod : 0.466
pp3v3_upc_xa_ldo : 0.482
pp1v1_upc_xa_ldo_bmc : 0.498
pp1v8_upc_xa_ldoa : 0.503

u3200
pp1v8_upc_xb_ldod : 0.460
pp3v3_upc_xb_ldo : 0.483
pp1v1_upc_xb_ldo_bmc : 0.477
pp1v8_upc_xb_ldoa : 0.496

ub300:
pp1v8_upc_ta_ldod : 0.453
pp3v3_upc_ta_ldo : 0.450
pp1v1_upc_ta_ldo_bmc : 0.475
pp1v8_upc_ta_ldoa : 0.000

ub400:
pp1v8_upc_tb_ldod : 0L ( so nothing? ) groundpin is 0.000
pp3v3_upc_tb_ldo : 0L again
pp1v1_upc_tb_ldo_bmc : 0.478
pp1v8_upc_tb_ldoa : 0L again

I got a funny feeling about UB400 .
What do you think is up?
Thanks again!

[mon2]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

ub300:
pp1v8_upc_ta_ldod : 0.453
pp3v3_upc_ta_ldo : 0.450
pp1v1_upc_ta_ldo_bmc : 0.475
pp1v8_upc_ta_ldoa : 0.000

ub400:
pp1v8_upc_tb_ldod : 0L ( so nothing? ) groundpin is 0.000
pp3v3_upc_tb_ldo : 0L again
pp1v1_upc_tb_ldo_bmc : 0.478
pp1v8_upc_tb_ldoa : 0L again

I think that both UB300 & UB400 have issues.

Configure your meter in resistance mode.

For UB300, measure & post the resistance to ground of the pp1v8_upc_ta_ldoa rail.

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

I think that both UB300 & UB400 have issues.

Configure your meter in resistance mode.

For UB300, measure & post the resistance to ground of the pp1v8_upc_ta_ldoa rail.

Hi, thank you for the quick reply!
I measure about 0.9 Ohm in the beginning and then it slowly drops to 0 in about 20 seconds.
Measuring the ground pin of that cap shows 0 first and then goes up a bit.

bad cap ? Measuring in bleep mode gives bleep, so looks like a short on it.

[mon2]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Yes, could be a bad cap. What is the history of this CD3215 ? Was it replaced?

If yes, could also be soldering of the replacement part.

There is only 1 cap on this rail - see attached. Remove it and check the resistance to ground again for the same rail.

If there is still a short then the fault is in the soldering.

Proceed to apply flux on the top of this IC and hover over the CD3215 in circles till you cover the top surface with enough heat to melt the balls.

Use tweezers to gently nudge the IC - 'make it dance'. Then the IC will naturally bounce back into position - do this 2-3 times and the chip should settle onto the proper pads. Remove the heat. Allow it to cool and check the resistance of this rail again.

If the rail does return to normal (it should) then place the innocent cap back on, unless the cap is guilty.

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Yes, could be a bad cap. What is the history of this CD3215 ? Was it replaced?

If yes, could also be soldering of the replacement part.

There is only 1 cap on this rail - see attached. Remove it and check the resistance to ground again for the same rail.

If there is still a short then the fault is in the soldering.

Proceed to apply flux on the top of this IC and hover over the CD3215 in circles till you cover the top surface with enough heat to melt the balls.

Use tweezers to gently nudge the IC - 'make it dance'. Then the IC will naturally bounce back into position - do this 2-3 times and the chip should settle onto the proper pads. Remove the heat. Allow it to cool and check the resistance of this rail again.

If the rail does return to normal (it should) then place the innocent cap back on, unless the cap is guilty.

I was a bit confused, but I think you mean CB306 because it is the LDOA rail?
CB305 resistance was very high.

I moved CB300 - it was replaced before - after that CB306 reading is better : 0.484 with diode mode on ldoa rail .

New diode readings:
ub300:
pp1v8_upc_ta_ldod : 0.443
pp3v3_upc_ta_ldo : 0.466
pp1v1_upc_ta_ldo_bmc : 0.471
pp1v8_upc_ta_ldoa : 0.487

ub400 after same treatment:
pp1v8_upc_tb_ldod : 0 - the cap cb405 is off
pp3v3_upc_tb_ldo : 0.567
pp1v1_upc_tb_ldo_bmc : 0.473
pp1v8_upc_tb_ldoa : 0L

Does this mean the UB400 is bad or anything else?
Not connected properly when measuring 0L ?
I will try to replace it again, or move again, this one needs a lot of heat to move and CB305 came off along the way .

Thanks for the help, seems UB300 is ok now?

[mon2]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

Yes, ub300 looks good now.

But ub400 needs some love.

Apply flux and reflow it. We want similar diode readings like ub300.

[openminded]

Re: MacBook Pro 15" 2017 A1707 Touchbar No power

man, what a journey ! Could not get ub400 4th point to work. It came off eventually, but I had no reballing tools. Felt lucky, cleaned and fluxed and got it back on with all LDO readings between 0.45 and 0.49 now!
2 caps came off, took an hour to get back, but made it!

All excited, but this is the situation now:
Upper ubc-c port only went on in one plug direction - then it shows 5.19 volt, but now 0.565 amps ( was much lower before, like 0.015-0.150).
Felt that UB300 became warm, so it seems sometimes goes wrong there.

Unplugged in time and still have same LDO reading on UB300 about, so it seems fine.
The other ports don´t do anything at the moment, neither direction.

I am wondering if I got further or not ?
I feel stuck again, although I am happy with the newly acquired understanding and skills.

Happy to get any tips to proceed. Thank you