Macbook pro touchbar 820-00239

[fozzo]

Hello guys, I've got this board in for repair with no power. Customer said it just stopped working from a day to another. Board looks immaculate, no one touched before me and there is no signs of liquid as far as I can see. Usb anmeter showed 0V and 0A. I went ahead to check ppbus_g3h and it was shorted to ground. I removed f7000 to discover short was on pin2. I had a visual inspection and found a capacitor very ugly which was c6425. I removed It and short was gone. After placing back f7000 the usb anmeter was acting like 1.27v, 2.79v then 4.99v with 0.20A (same behaviour on all ports) but after, let's say 15 seconds, it slowly decrease to 4.99v 0a. Checked all power rails while it takes 0.20a and it seems they all come right. Also all_sys_pwrgd appair but then when it decrease to 0a all rails disappear except of State 5 rails (such as pp3v3_s5, pp5v_s5) which are stable at 5v. ppbus_g3h sits stable at 13.01V and so pp3v3_g3h at 3.3v. Anmeter never show 20v as expected. Any guidance would be very apreciated.

[mon2]

Re: Macbook pro touchbar 820-00239

Study the following boot sequence and post your updates:

https://logi.wiki/index.php/CD3215_B...on_the_charger

[fozzo]

Re: Macbook pro touchbar 820-00239

Meanwhile I took some measure on cd3215 lines. Diode mode

USBC_XA_CC1 .592
USBC_XA_CC2 .595
USBC_XB_CC1 .592
USBC_XB_CC2 .597
USBC_TA_CC1 .594
USBC_TA_CC2 .597
USBC_TB_CC1 .597
USBC_TB_CC2 .600

If I put charger

USBC_XA_CC1 cycle 2v - 1.8v 0.89v and so on
USBC_XA_CC2 cycle 2v - 1.8v 0.89v and so on
USBC_XB_CC1 cycle 2v - 1.8v 0.89v and so on
USBC_XB_CC2 cycle 2v - 1.8v 0.89v and so on
USBC_TA_CC1 sits at 0v
USBC_TA_CC2 sits at 0v
USBC_TB_CC1 cycle 2v - 1.8v 0.89v and so on
USBC_TB_CC2 cycle 2v - 1.8v 0.89v and so on

It seems like ub300 have problems, I checked all resistors near it and look fine (almoust same ohm as schematics). I also checked for any short but didn't find. I'm going to take a look at the schema provided.

[mon2]

Re: Macbook pro touchbar 820-00239

Check and post also the diode readings of the usb data lines of each CD3215 (D+ / D-).

If one CD3215 is defective, you will not be able to negotiate the 20v power delivery contract.

If you have not done so already, remove the logic board out of the enclosure and detach the battery, keyboard, touch bar and the usb type c bridge boards. Inspect the contacts of each type c bridge board for damage. Use only one bridge board to see if logic board can stabilize at 5v.

Suggest to check again with the isolated logic board, the resistance to ground of each coil. The +3v42 rail is stable and always on? Confirm the dual diode powering the +3v42 regulator is ok. Check the resistance to ground on the cathode of the dual diode for shorted caps.

[fozzo]

Re: Macbook pro touchbar 820-00239

Checked schema you gave and took some meauremnt as follow

d6902
pin 1 12.9
pin 2 20.2
pin 3 19.9

r6915 3.3v

u3200
F3001 20.2v each side
PP1V8_UPC_XB_LDOA 1.79v
PP1V8_UPC_XB_LDOD 1.79v
PP1V1_UPC_XB_LDO_BMC 1.1v
PP3V3_UPC_XB_LDO 3.37v

u3100
F3000 20.v each side
PP1V8_UPC_XA_LDOA 1.78v
PP1V8_UPC_XA_LDOD 1.79v
PP1V1_UPC_XA_LDO_BMC 1.1v
PP3V3_UPC_XA_LDO 3.36v

ub400
FB201 20.2v each side
PP1V8_UPC_TB_LDOA 1.8v
PP1V8_UPC_TB_LDOD 1.78v
PP1V1_UPC_TB_LDO_BMC 1.11v
PP3V3_UPC_TB_LDO 3.36v

ub300
fb200 20.2v each side
PP1V8_UPC_TA_LDOA 1.8v
PP1V8_UPC_TA_LDOD 1.79v
PP1V1_UPC_TA_LDO_BMC 1.1v
PP3V3_UPC_TA_LDO 3.33v

u7000
smc_rst_l 3.3v
chgr_amon 0v
chgr_bmon 0v
smc_aux_ok 3.4v

u5000
PP3V0_G3H_AVREF_SMC 2.99v
PM_BATLOW_L 3.3v

Do I miss anything?
Will check what you told me

[fozzo]

Re: Macbook pro touchbar 820-00239

"usb data lines of each CD3215 (D+ / D-)" I can't seem to find, what are rails name?

Logic board is on my desk, I never place back in the case since it doesn't boot.

What coils are you talking about? If the big ones

L7270 55ohm .012 diode both sides
L7220 6.5ohm diode .007 both sides
L7210 6.5ohm diode .007 both sides
L7410 3ohm diode .003 both sides
L7420 3ohm diode .003 both sides
L7430 3ohm diode .003 both sides

+3v42 rail do you mean pp3v3_g3h? if so yes stable

With dual diode you mean d6902?

d6902 resistance
pin 1 1.1Mohm (decreasing)
pin 2 367kohm
pin 3 1.1Mohm (decreasing)

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Is one of the cd3215 getting warmer than the other?
Check LDO Outputs on all CD3215

As you dont have 20v being requested but ppbus_g3h and pp3v3_g3h are present, one of the cd`s could be bad

[fozzo]

Re: Macbook pro touchbar 820-00239

I’ve double checked under thermal camera but none doesnt seem seem to get hot.

[mon2]

Re: Macbook pro touchbar 820-00239

Did you note above correctly that 20v is present on the FBxxx parts local to each cd3215?

If yes, then your logic board has negotiated the 20v contract with your external power adapter.

To measure the usb data lines, you will remove all power and check the D+ / D- pins through a type C breakout board. This can be tricky but safe as all power is off. They sell similar boards for measuring the tristar mux diode values for lightning connectors. Handy to have here for also the type c measurements.

Based on the 20v reading, your cd3215s appear to be fine. You can apply the power adapter on each cd3215, one at a time, to confirm each can negotiate the 20v contract which validates that each CCx pair is ok.

The next focus should be on testing each power rail to determine why the logic board degrades over time.

[fozzo]

Re: Macbook pro touchbar 820-00239

Yes I checked each fuse for each cd is getting power correctly.

I will diode all D+/- lines and report back, don't have a donor or working board hereto compare though.

I already applied power to each CD and all seems fine except for the strange behaviour on ub300 which i noted before

USBC_TA_CC1 sits at 0v
USBC_TA_CC2 sits at 0v

while all other cycle between 2v and 0.8v.

I'm not so familiar with those new boards so I wonder if is normal that chgr_amon and chgr_bmon are both at 0v at all time.

I can say I alerady checked each power line and they are all present untill charger drop to 0amps but I will check again later. I apreciate your kidness and help

[mon2]

Re: Macbook pro touchbar 820-00239

USBC_TA_CC1 sits at 0v
USBC_TA_CC2 sits at 0v

Could be the show stoppers. Try a known good type c paddle board to test the same possible defective cd3215 controller. If correct, this port will not allow for the proper 20v contracts. A sub $100 usd power delivery bus analyzer would be a good tool to use here. ST semiconductor has such a tool, there are others as well.

The CCx pins and lines are used to communicate the power delivery contracts using the biphase interface. Each such ACE controller communicates to the host over I2C lines. If an ACE controller is defective, 20v cannot be reached with the type c adapter.

Please confirm again that 20v is NOT working as you listed this value above on each FBxxx part. Or that it does work but only for a short period?

Typically if the cd3215 is defective ( common issue ), the controller has to be replaced.

I think this damage is due to use of non-Apple chargers or shorting of Vbus to CCx lines during removal while hot at 20v contract. The more current type c power delivery controllers offer protection against this event.

[fozzo]

Re: Macbook pro touchbar 820-00239

Hi again, sorry for late answer but I did have other repairs on queue. I took all d+/- diode reading on both connector and as I was expecting there is a low value on JB500, here is the list

J3300

USBC_XB_R2D_N<1> OL
USBC_XB_R2D_P<1> OL
USBC_XB_R2D_N<2> OL
USBC_XB_R2D_P<2> OL
USBC_XB_D2R_N<1> .346
USBC_XB_D2R_P<1> .345
USBC_XB_D2R_N<2> .345
USBC_XB_D2R_P<2> .346
USBC_XA_USB_DBG_BOT_N OL
USBC_XA_USB_DBG_BOT_P OL
USBC_XA_R2D_P<1> OL
USBC_XA_R2D_N<1> OL
USBC_XA_USB_DBG_TOP_P OL
USBC_XA_USB_DBG_TOP_N OL
USBC_XA_R2D_P<2> OL
USBC_XA_R2D_N<2> OL
USBC_XA_D2R_P<1> .344
USBC_XA_D2R_N<1> .344
USBC_XA_D2R_P<2> .345
USBC_XA_D2R_N<2> .344

JB500

USBC_TB_R2D_N<1> OL
USBC_TB_R2D_P<1> OL
USBC_TB_R2D_N<2> OL
USBC_TB_R2D_P<2> OL
USBC_TB_D2R_N<1> .331
USBC_TB_D2R_P<1> .330
USBC_TB_D2R_N<2> .332
USBC_TB_D2R_P<2> .330
USBC_TA_R2D_P<1> OL
USBC_TA_R2D_N<1> OL
USBC_TA_R2D_P<2> OL
USBC_TA_R2D_N<2> OL
USBC_TA_D2R_P<1> .331
USBC_TA_D2R_N<1> .330
USBC_TA_D2R_P<2> .329
USBC_TA_D2R_N<2> .113

I was not tricky to get reading of each pin as I'm familiar with iphone and mobile where the space is smaller, the tricky part was to take all note! Anyway USBC_TA_D2R_N<2> .113 looks way different from its positive, all other pairs look almouost identical so I think here there is a problem. According to schematics this pin goes to a diode db527 and inside UB000. I'd love to repace this diode but I don't have any board here same year, any idea where I could find on older boards?

[fozzo]

Re: Macbook pro touchbar 820-00239

I’m already using my good paddler. I will check your last answer tomorrow meanwhile I will check that diode datasheet to see if I find anything equivalent.

[mon2]

Re: Macbook pro touchbar 820-00239

hi.

1) the datasheets for the ESD diodes for the USB protection used on this logic board is attached. Wonder why Apple made these parts so large ?

If you are comfortable to do this, you could temporarily remove the 2-4 diodes on this USB interconnect and see if the readings improve. If they do not, then the diodes are not the issue. Keep in mind, 2 diodes for each D+/D- pair. Then another 2 diodes for the opposite side of the C connector blade. Then zeners for the CCx line protection (top and then again bottom of the blade).

You should be able to pickup the ONSEMI ESD parts from main stream distributors like Arrow or similar.

https://www.arrow.com/en/products/es...-semiconductor

Do review the full ESD diode network for the TOP side of the USB C connector and also the BOTTOM side of the USB C connector blade. That is, if you see any discoloration or suspect these parts as an issue, they should be replaced. The ESD components are sacrificial and they 'took one for the team' and are no longer good to use if they have been hit with a hard transient. Perhaps you can inspect each with your microscope.

Apple is using some zeners to protect the CCx lines but are 0201 parts - more joy !!!

I would buy 100 or more as they are so tiny and easy to lose.

2) technically, these ESD diodes are not required for immediate testing. there is a small possibility that the ESD diode is damaged and causing the readings you are observing. However, many internet articles and posts (including this forum) report that the actual CD3215 is the component that needs to be replaced. These controllers are common to Asia and any shop with macbook repair parts. The guy with the ponytail in Germany should have them but perhaps you can just order from Aliexpress as well.

You may be able to get lucky to buy a donor logic board off Ebay but the pricing will vary. Then you will have to remove and reball the pulled part before it can be applied here. Personally found the stencils to be not fun to use and only recently purchase a DIRECT heat stencil. Not tested yet. Our fully automatic BGA rework station should arrive by the end of this week. Has vision, etc. which will help our fading eyesight.

So your grocery list now includes:

a) ONSEMI ESD8011 (as per attached datasheet) - 100+

b) the zeners used by Apple on the same connector (0201 footprint) - 50+

c) CD3215 ACE Controller - be sure to buy the same one that is on your logic board - best if 100% new so the balls are fresh.

[fozzo]

Re: Macbook pro touchbar 820-00239

Thanks for the complete info. I will check under my microscope tomorrow all those diodes to see if I see anything bad. I would prefer to order a donor board and reball the cds, I'm familiar with this, I just reballed an iPhone 7 Intel baseband today which I guess would be almoust same difficult as cd. I read many saying that asian sourced chip might be fake and I don't want to lose so much time waiting for something which will not work. I will need a stencil for those though. I will then order those diodes (both zeners and esd), they might be always usefull with those boards. I will hit you back tomorrow with some news and probably a question about what to remove to understand which pair are on the opposite side of the blade.

I just had a look at this CD stencil and it looks way easier than an iPhone 7 baseband

[fozzo]

Re: Macbook pro touchbar 820-00239



Hello again. I checked diodes and I don't see anything strange here then i checked zener diode and it looked ugly, kinda broken. By luck iphone 7 plus has the same diode so i changed it but it made no difference. I'd like to give a shot without either diodes and zener diodes which you told me yesterday just to see if it makes any difference. You told me to remove 4 diodes and its zener protector, i think you meant the four in the picture. Am I wrong? The highlighed one is the one with low measurement.

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Hi fozzo,

i am facing the same problem.
Did you find a solution?

[fozzo]

Re: Macbook pro touchbar 820-00239

Hello again, finally I received parts. I changed all in one the two zener diodes., two Onsemi ESD8011 diodes and two relative cap, as well as CD3215 ACE Controller but after changing all of the USBC_TA_D2R_N<2> was still at .113. I pluged charger and ampmeter and it went straight to 20v, reassembled the machine and I got a nice red battery and after a while a nice chime and apple logo and home screen. I don’t know what was actually the culprit, I preferred to do all in one to save lot of heat to the motherboard. Still need to test all but it seems the major problem have been solved. By the way CD3215 i Used is a reballed one taken from original motherboard, here are pictures

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Could you please explain me which parts exactly are those zener diodes, Onsemi diodes and caps?

Gracie mille

My board is actally without any cd3215, i am waiting parts to arrive

[fozzo]

Re: Macbook pro touchbar 820-00239

Hello there, sorry for delay.
Actually I changed

DZB501, CB314, UB300 and DB527