MacBook Pro A2159 - No power

[Dallas90]

Hi everyone, I really need your help with a repair case.

I got a Macbook Pro A2159 820-01598
and the problem is that it does not power on. USB meter reading 5V 0.40-70A

Visual inspection:
L5100 - Burned / 0402 - 1.2UH-20%-0.12A-1.17OHM
(Removed) didn't solve the problem. Could it be fixed temporarily with a jumper wire?
U9000 - Missing Chip on board / 338S00410-A0
I don't know if there should be empty or not, but it does look
Like it was removed.


Multimeter readings:
F7000 - 12.28v - Abnormal?- T2 ROM Firmware fail?
C3200 - 00.38V - Abnormal, should be 3.3V.
C3205 - 1.54V - Doesn't know if it's normal or not?
C3208 - 3.45V - Doesn't know if it's normal or not?


Thermal camera inspection:
The only thing that gets ”hot” (30C) or lights up/blinking on the board is U6903, L6900, and L6901 are tested with a multimeter and 12V is present.
A video from my thermal inspection could be sent if requested.



Readings from test equipment S-UEM2:
If you look at the attached image, there are some abnormal readings on pins 46,47, 48, and 49 right?

https://pasteboard.co/ZByTtktFCQww.jpg

[reformatt]

Re: MacBook Pro A2159 - No power

T2 machine, you need working SSD's for T2 to load Bridge OS. U9000 provides power rails to the NAND's. It's removal indicates there was probably a short on one of them. Do voltage injection of 0.9V and see if any of them get hot via thermal camera.

I'd suspect it was liquid damaged, given that L5100 is burnt as well. Does it look like it was in an ultrasonic cleaner?

[Dallas90]

Re: MacBook Pro A2159 - No power

Hi and thanks for your reply.

It does not look like it was cleaned, lots of dust on the board.
I connected the laptop to my own Macbook and tried to get it in DFU mode.
It appeared in Apple configurator 2 but a few seconds later the DFU icon disappeared.

Where shall I inject the Voltage, and which line/component?
0.9V and how much A? shall I inject it without the u9000 installed or do you recommend that i order a new chip and install it and then test inject voltage?

[Dallas90]

Re: MacBook Pro A2159 - No power

Just to clarify, the chip was not present on the board at all when I got the laptop, obviously, someone worked on it before.

[reformatt]

Re: MacBook Pro A2159 - No power

BridgeOS (and EFI BIOS) is reloaded during DFU revive/repair so has to have functional NAND's. Pointless to do that until that is resolved.

Check impedance on L9020/9021, and the 1.8V line at L9030 and voltage injection from there. You have to wonder why the last guy gave up? Were the NAND's damaged, or just didn't have a replacement IC. Was that IC even faulty? This is the problem working on a board that has been previously messed with.

[Dallas90]

Re: MacBook Pro A2159 - No power

Hi again,

Please take a look at the image in the link, if you don't want to open it PM me with your email and I will send it there.

It looked like this, the scratches and a lot of components are missing if it's like you said, there should be a chip.

the part you asked me to inject voltage to is also missing if you look at the image.

[reformatt]

Re: MacBook Pro A2159 - No power

Obviously reworked as U9000, a bunch of passives and the coils are missing, possibly this board was used as a donor to fix another board. It doesn't look like U8800 was ever fitted so I'd guess this board only had 2 NAND's (U8600 is underfilled and U8800 shows no evidence of clean up or scraping).

If the board was used as a donor (which it looks like it did), you'd assume it's either iCloud/MDM locked, or the T2/CPU is dead.

[Dallas90]

Re: MacBook Pro A2159 - No power

Hi again, after some research i found out that, there is no missing chip.. there should not be a chip there on this board, only if there is 4 Nand chips.

the fun part is that I already ordered a new chip haha..

So I guess its because of the ELC180 that lights up on thermal camera that is the problem here, and of course the burned component L5100.

Do you know if there is a similar component that I can use from my donor boards?
I got a A1466 and a A1932.

Thanks in advance.