Toshiba m2 died

[Gokhann]

Here is a picture of the 1.8 load switch area.

There is not much , there is two cap and a filter. no short.
Cap on the left, bottom side is GND.

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[fzabkar]

All the supply voltages seem OK, and there are no longer any shorts, but something still appears to be overloading the USB port.

I don't know the functions of SD, 6AGRVI and XM.

Did you check the output voltage and resistance to ground at this IC?

Unknown_load_switch.jpg (70.95 KiB) Viewed 16678 times

[Gokhann]

Now with a twin

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[Gokhann]

All the supply voltages seem OK, and there are no longer any shorts, but something still appears to be overloading the USB port.

I don't know the functions of SD, 6AGRVI and XM.

Did you check the output voltage and resistance to ground at this IC?

The attachment Unknown_load_switch.jpg is no longer available

Here is a diode mode measurement to compare a good and the dead hdd. I cant see any difference

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[Gokhann]

here is voltage measurement on working and the dead hdd
Yellow boxes shows the abnormal values

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[fzabkar]

Is it possible that the part which I am guessing is an inductor is open circuit? If so, and if there is no short circuit across the capacitor (?), it should be OK to bridge it.

I'm thinking that the inductor and capacitor may constitute a low pass LC filter.

However, that doesn't explain why the USB port is still overloading. :-???

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[fzabkar]

These 3 components are LC low pass filters.

https://www.murata.com/-/media/webrenewal/support/library/catalog/products/filter/lc/k99e_l0270.ashx?la=en&cvid=20160218003958490200

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[fzabkar]

I think that 6AGRVI may be equivalent in function to the following chip:

TXB0302DQMR, Texas Instruments, 2-Bit Bidirectional Voltage-Level Translator with Automatic Direction Sensing, 0.9V - 3.6V, marking 77A, MicroQFN-8 / X2SON:
https://www.ti.com/lit/ds/symlink/txb0302.pdf

This chip is found on an XG5 SSD.

https://www.thessdreview.com/our-reviews/nvme/toshiba-xg5-nvme-ssd-review-3d-bics-64-layer-flash-shines/
https://www.thessdreview.com/wp-content/uploads/2017/06/121A9821-1024x615.jpg
https://images.anandtech.com/doci/11663/imgp2825-cropped.jpg

[fzabkar]

I would map out the power supply hierarchy by identifying the buck/LDO regulators and their respective load switches, filters and loads. Each of the loads (NAND, controller, SDRAM, temp sensor) would have small bypass capacitors adjacent to them. Once you have this big picture, troubleshooting will be a LOT easier.

Not all bucks will have a load switch (because the MCU must have at least one always-on supply).

Code:

3.3Vin ---> Load Switch --> PMIC --> LDO ---------------------------------------> Load #0
                                 --> Buck #1 --> Load Switch #1 --> Filter #1 --> Load #1
                                 --> Buck #2 --> Load Switch #2 --> Filter #2 --> Load #2
                                     ...                                          ...
                                 --> Buck #6 --> Load Switch #6 --> Filter #6 --> Load #6

[Gokhann]

I would map out the power supply hierarchy by identifying the buck/LDO regulators and their respective load switches, filters and loads. Each of the loads (NAND, controller, SDRAM, temp sensor) would have small bypass capacitors adjacent to them. Once you have this big picture, troubleshooting will be a LOT easier.

Not all bucks will have a load switch (because the MCU must have at least one always-on supply).

Code:

3.3Vin ---> Load Switch --> PMIC --> LDO ---------------------------------------> Load #0
                                 --> Buck #1 --> Load Switch #1 --> Filter #1 --> Load #1
                                 --> Buck #2 --> Load Switch #2 --> Filter #2 --> Load #2
                                     ...                                          ...
                                 --> Buck #6 --> Load Switch #6 --> Filter #6 --> Load #6

I was thinking about unsolder the 1.8 ldo from working hdd and reball and soldered on dead one. And continue with rest of the components around it until it works.

Or do you want me to make a scahemtic how the ldo's around connected?

[Gokhann]

Here is a better pic of the 1.8v ldo
Yes there is a cap and filter.

The Cap is not shorted.
The filter is open as it should.

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[Gokhann]

Finally

After shorting the 1.8V ldo, it came a live

What a relief.

Thanks so much for your help and guidance.
Without you, i couldnt do it

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[evs9]

amazing read!!!
glad you're safe & got your data!
incredible work!

[netopr]

congratulations!