Toshiba m2 died

[fzabkar]

I'm stumped. It does seem that CH4 is not regulating, though.

Would it be possible for you to remove the inductor on CH4 and see whether the supply remains alive?

Or perhaps you could wait for someone else to chime in and offer some better advice?

Last edited by fzabkar on January 2nd, 2024, 16:56, edited 1 time in total.

[Gokhann]

i re-injected, now with 3.3V in

here are the result

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[fzabkar]

Are you still limiting the current? I confess that these results make no sense to me.

Edit: I see you have edited your image. Now the results make sense. It seems that you just need to increase the current limit.

Last edited by fzabkar on January 2nd, 2024, 17:04, edited 1 time in total.

[Gokhann]

Im not sure about the CH4, after measuring it twice it gave in the first run 3V, but now after injecting 3.3V , now it gives med 0.79V.

[Gokhann]

Are you still limiting the current? I confess that these results make no sense to me.

ah my silly brain, stopped working, yes there were current limit on, now i set the limit to 500mA and ch1 voltage raised to 2.52V. Give me a min, i have fresh voltages

[fzabkar]

Im not sure about the CH4, after measuring it twice it gave in the first run 3V, but now after injecting 3.3V , now it gives med 0.79V.

This would make sense if the feedback ball of the PMIC was intermittently open circuit on that channel. In other words, the PMIC incorrectly senses that there is no output on that channel, and it then drives the MOSFET to its limits in an attempt to increase the voltage.

[Gokhann]

Im not sure about the CH4, after measuring it twice it gave in the first run 3V, but now after injecting 3.3V , now it gives med 0.79V.

This would make sense if the feedback ball of the PMIC was intermittently open circuit on that channel. In other words, the PMIC incorrectly senses that there is no output on that channel, and it then drives the MOSFET to its limits in an attempt to increase the voltage.

Here the results with current limit of 0.5A at 3.3V input

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[fzabkar]

All looks good to me.

[Gokhann]

All looks good to me.

Yes, same to me too.
So all powersupply block is working as it should. Now it leaves me with the hotspot near the one of RAM block.

can it be one of the ram block is dead?

[fzabkar]

Are you referring to the 64C temperature reading? The only thing that would make sense is if a capacitor were "leaking". A shorted IC would be hottest in the centre where its silicon die is located. You should be able to detect a hot capacitor with your fingers, or you could add a drop of IPA and see how fast it evaporates.

[Lardman]

I'd check again with a completely different adapter. All the test you've just done have come from injecting the voltage rather than powering from the connector. You might also want to try pressing on the drive and chip in case it's a cracked joint.

[Gokhann]

Are you referring to the 64C temperature reading? The only thing that would make sense is if a capacitor were "leaking". A shorted IC would be hottest in the centre where its silicon die is located. You should be able to detect a hot capacitor with your fingers, or you could add a drop of IPA and see how fast it evaporates.

Yeah, the problem is that the 64 deg reading i got yesterday, is not able to be reperatet now. I dont understand why it doesnt start up or gets hot.

I need to find a few more usb c cabel before i give up.

But i appreaciate your help. You have been such a big help and mentor for my first m2 repair. Tahnk you so much again and again

[fzabkar]

You might want to confirm that the same voltages appear at the inputs and outputs of each load switch.

I notice that channel 4 feeds the "XM" IC, but I don't know what it does. Maybe it's another load switch?

[Gokhann]

You might want to confirm that the same voltages appear at the inputs and outputs of each load switch.

I notice that channel 4 feeds the "XM" IC, but I don't know what it does. Maybe it's another load switch?

Here re voltages after injecting 3.3V at 500mA.

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[fzabkar]

It looks like the 1.8V load switch has failed. I would identify those components which are connected to the output of this switch, in particular the small bypass capacitors, especially the ones in the 64C area. It might be difficult to find the culprit if the fault is/was intermittent.

You may be able to recover the data by bypassing this switch, as you suggested earlier, but I would first try to find the problematic component. If you don't, then the PMIC may be directly exposed to any short that resurfaces.

I'm still bothered by your results for CH4. Hopefully this problem has gone away.

Last edited by fzabkar on January 2nd, 2024, 19:14, edited 1 time in total.

[Gokhann]

It looks like the 1.8V load switch has failed. I would identify those components which are connected to the output of this switch, in particular the small bypass capacitors. It might be difficult to find the culprit if the fault is/was intermittent.

It look like we are back at the broken load switch again;) dont you think the broken side has effected?

I tried earlier to short in and out for switch, but i didnt see any reaction or changes

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[Gokhann]

It looks like the 1.8V load switch has failed. I would identify those components which are connected to the output of this switch, in particular the small bypass capacitors, especially the ones in the 64C area. It might be difficult to find the culprit if the fault is/was intermittent.

You may be able to recover the data by bypassing this switch, as you suggested earlier, but I would first try to find the problematic component. If you don't, then the PMIC may be directly exposed to any short that resurfaces.

I'm still bothered by your results for CH4. Hopefully this problem has gone away.

When you say ch4, do you mean the 1.2V output? Whats wrong with that?
I will try to find the bad component first otherwise i I will try to bypass it tomorrow and see what happens

[fzabkar]

I was referring to your original measurement of 3.06V. That makes me uncomfortable, unless it was an error on your part.

[fzabkar]

It looks like the 1.8V load switch has failed. I would identify those components which are connected to the output of this switch, in particular the small bypass capacitors. It might be difficult to find the culprit if the fault is/was intermittent.

It look like we are back at the broken load switch again;) dont you think the broken side has effected?

I tried earlier to short in and out for switch, but i didnt see any reaction or changes

It looks like the short propagated all the way back to the host PC. I never expected that.

After bridging the switch, does the voltage remain at 1.8V? Is the SSD still power cycling now?

[Gokhann]

I had to measure all the components again, directly supplied throug usb., no external injection.

there are 3 places where i am able to measure a voltage

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