820-00239-A no ssd (question mark folder)

[mbcontrol]

Apple gave the customer the diagnose that the ssd is dead - logicboard must be changed.
I can't find any liquide damage. The board brings the question mark folder.

The hall-sensor on the right side was gone - i put a donor part on it.
R8604 looked like somebody did some work on it. so i recognized that it is an 10k resistor. in the schematic is an 100k resistor shown. so i changed it to 100k.

Here are my measurements. Can you help me to understand which signal is ok? I have not much experience with ssd circuits and i don't understand the low-signals. If a signal is named with an L at the end - must it than be low to be ok?

pp1v2_ssd_hot = 1.231v
pp3v3_s5_ssd = 3.364v
pp3v3_2v7_nand_vcc = 2.685v
pp1v8_ssd_cold = 1.823v
pp2v7_nand_pvcc = 5.137v
pp2v7_nand_vcc = 5.122v

SSD_BOOT_LB_L (Pin4 J9600) = 1.781v
SSD_PWR_EN_L (Pin5 J9600) = 0v
SSD_PWR_EN_LB_L (Pin6 J9600) = 0v
STORAGE_LB_EN (Pin8 J9600) = 3.329v

SSD_RESET_L (Pin11 J9600) = 3.324v
SSD_RESET_LB_L (Pin12 J9600) = 3.324v
SSD_CLKREQ_L (Pin13 J9600) = 3.325v
SSD_PCIE_CLKREQ_LB_L (Pin14 J9600) = 3.326v

P0V9_FIXED_SW (L9300 Pin1) = 0.904v
P0V9_REG_SW0 (L9320 Pin1) = 0.854v

 

[2informaticos]

Any history from client?

"If a signal is named with an L at the end - must it than be low to be ok?"
OK and active is not the same thing!
Depends what that signal means.

If you have "X_RESET_L" signal, 0V means active; so no good, didn't see any device working in reset mode yet.
But something like "X_EN_L" is expected to be low (0V) in working state.

 

[mbcontrol]

I'm back working at this board. Thanks for the explanation of the l-signals, that helps me a lot for better understanding.

The customer gave me this information ...
"When using Final Cut Pro, we always had the case that the system was very slow, leading to a crash (complete freezing). This effect occurred particularly in the somewhat larger projects, so it was probably load-dependent. Working with other programs was largely problem-free.
In the last few days before the total failure, the effect increased so much that it was hardly possible to work with Final Cut Pro."

And here are actual measurements (SSD-Side):
J9600 Pin 6: SSD_PWR_EN_LB_L = 0V
J9600 Pin 8: STORAGE_LB_EN = 3,33V
J9600 Pin 4: SSD_BOOT_LB_L = 1,78V
J9600 Pin 2: PP5V_S4_P2V7NAND_LB = 5,14V
J9600 Pin 44: PPVIN_2V7NAND_LB = 13,06V
J9600 Pin 38/40/42/46: PP3V3_S5_SSD_LB = 3,36V

I have now also changed U9300 (JIC) - has brought no change

 

[2informaticos]

With J9600 closed, check continuity from left to right side for all its lines.