A1706 MacBook Pro mid 2017 no internal SSD/NAND 820-00923

[slimmy182]

Hello people.

I've purchased this mid 2017 13" MacBook Pro touchbar, logic board number 820-00923 who don't recognize internal SSD anymore. When powered on it display the question mark. Seller says that it simply stop working one day, no liquid spill, failed update or so. It can operate perfectly installing MacOs on external drive, but internal SSD storage does not show up in online recovery nor when external hard drive is plugged it to launch MacOs.

I decided to open it and try to resolve the problem. Never been opened or worked before for sure.

Inspecting the board under the microscope show this two little spot of corrosion:

probe point TP[1]TP_Q3100_DRAIN , picture show before and after cleaning



and LB300


I can't find any other spot or phisical damage on this board.

J9600 (lifeboat port) also look good.

I can confirm CD3215 ACE controller works fine, it does negotiate the 20V and I can boot up and charge the battery.

As mentionend many times as possible trouble point, R9350 related to PPVIN_2V7NAND_LB measures 13.8V in both test point and pin1 and 1.58V on pin 2.

I'm not so good looking at schematics as this is not my work, just hobby for myself. I made those measurement taking a cue on other posts, so please forgive me if I'm completely wrong. Just wanna learn something and have fun.


C9126 - PP1V8_SSD_COLD - 1.8V diode mode 294 (2K scale)
C9304 - PP0V9_SSD_FIXED - 0.9V diode mode 294 (2K scale)
C8724 - PP1V2_SSD_HOT - 1.22V diode mode 328 (2K scale)
C8714 - PP1V8_SSD_HOT - 1.8V diode mode 408 (2K scale)
C8732 - PP1V2_SSD_COLD - 1.22V diode mode 282 (2K scale)
C9323 - PP0V9_SSD_REG - 0.9 diode mode 208 (2K scale)

I measured also PP3V3_S5_SSD and it's 3.34V.

I got 0 voltage at L9300/20/30/40 and L9400

C9422- PIN1 PP2V7_NAND_VCC 4.8V

SSD_BOOT_LB_L 1.62V
SSD_PWR_EN_LB_L 0V
STORAGE_LB_EN 3.05V
SSD_RESET_LB_L 3.05V
SSD_PCIE_CLKREQ_LB_L 3.18V
LPSR_EN_LB_L 3.05

at R9420 P2V7NAND_EN and PICCOLO_VEN1 are 0V

 

[2informaticos]

First of all, welcome to the forum!

"C9304 - PP0V9_SSD_FIXED - 0.9V diode mode 294 (2K scale)"
I'm not sure about your notations.
First, diode mode is not same as ohm (2K) scale; don't create more confusion.
Second, you've said 0V at L9300.

Please, post accurate information.

 

[slimmy182]

Damn, I dunno what happened. I’m pretty sure the first time I had readings.

took measures again:
C9126 - PP1V8_SSD_COLD - 0v
C9304 - PP0V9_SSD_FIXED - 0V
C8724 - PP1V2_SSD_HOT - 0V
C8714 - PP1V8_SSD_HOT - 0V
C8732 - PP1V2_SSD_COLD - 0v
C9323 - PP0V9_SSD_REG - 0v

PP3V3_S5_SSD and it's 3.34V.

I got 0 voltage at L9300/20/30/40 and L9400

C9422- PIN1 PP2V7_NAND_VCC 4.8V

SSD_BOOT_LB_L 1.62V
SSD_PWR_EN_LB_L 0V
STORAGE_LB_EN 3.05V
SSD_RESET_LB_L 3.05V
SSD_PCIE_CLKREQ_LB_L 3.18V
LPSR_EN_LB_L 3.05

at R9420 P2V7NAND_EN and PICCOLO_VEN1 are 0V


For diode mode: Red probe on ground, black probe in test point. Multimeter setting in continuity mode. Sorry for confusion.

 

[2informaticos]

Check if you have good contacts left/right for all lines of J9600.
If needed, remove the top plate and clean its contacts.

Inspect for corrosion on any trace SSD related; no matters if power rail, or signal line.

 

[slimmy182]

Unfortunately my multimeters probe are not so small to let me check left/right J9600 pin inside connector, but it seems they are fine. I posted pictures of both connector and top plate. I cleaned both anyway.

I really can't find any corrosion anywhere.

But taking a look in U9400, it seems like it has an hole on it! And it become extremely hot.





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[2informaticos]

"Unfortunately my multimeters probe are not so small to let me check left/right J9600 pin inside connector"
I meant to check continuity for left/right lines with J9600 connected.
You can find test points, or components pins connected to corresponding lines for test.

However, as U9400 is burnt, fix that problem first.
Replace U9400 and check also R9401/06 values.
Be sure to get good solders; if not, risk to burn Q9401 and NANDs.