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Sandisk 20-99-00121-1 Flash Drive missing component
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Author:  ptg [ September 30th, 2020, 14:04 ]
Post subject:  Sandisk 20-99-00121-1 Flash Drive missing component

Hi, I'm missing a component on this flash drive, which is preventing the flash drive from working. Right now, the light just blinks once, then no more life from the flash drive. Computers aren't recognizing the drive at all. I suspect that this missing component is the cause. Any help in identifying this component would be much appreciated.

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Author:  ddrecovery [ September 30th, 2020, 19:03 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

Is one side ground and other not?

Author:  ptg [ September 30th, 2020, 19:07 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

No, one side is .4V in diode mode and the other is .53V. Looks like one side is connected to pin 1 on the controller chip.

Author:  ddrecovery [ October 1st, 2020, 10:22 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

ptg wrote:
No, one side is .4V in diode mode and the other is .53V. Looks like one side is connected to pin 1 on the controller chip.

Are you measuring voltage of diode mode readings?

Author:  ptg [ October 1st, 2020, 10:50 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

Diode mode, not voltage with it powered on

Author:  arvika [ October 1st, 2020, 12:08 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

I do not have better photo.

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Author:  ptg [ October 1st, 2020, 18:38 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

Sorry, but I need the value of the component. Can you help with that?

arvika wrote:
I do not have better photo.

Author:  arvika [ October 2nd, 2020, 5:29 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

I do not have phisically this device in my lab, sorry.

Author:  jeremyb [ October 6th, 2020, 13:10 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

I have a few donor boards of that model, its a fixed inductor. I have no idea what the value is though.

Author:  ptg [ October 6th, 2020, 13:37 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

Thank you Jeremy. Yeah, I thought that I had tested a filter, but I guess I must not have. Anyways, the inductor did indeed fix the drive. Appreciate your response.

jeremyb wrote:
I have a few donor boards of that model, its a fixed inductor. I have no idea what the value is though.

Author:  fzabkar [ October 6th, 2020, 14:29 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

Measure the voltage on each side of the component.

Author:  jeremyb [ October 7th, 2020, 10:16 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

fzabkar wrote:
Measure the voltage on each side of the component.

3.2v on either side of the component

ptg wrote:
Thank you Jeremy. Yeah, I thought that I had tested a filter, but I guess I must not have. Anyways, the inductor did indeed fix the drive. Appreciate your response.

No problem, glad to of helped :-)

Author:  fzabkar [ October 7th, 2020, 15:07 ]
Post subject:  Re: Sandisk 20-99-00121-1 Flash Drive missing component

It looks like the inductor may be filtering the Vcc supply for the NAND. Measuring the voltages with the inductor removed would tell you whether the voltage was being generated internally or externally.

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