SanDisk X100 256G no BIOS detection

[alindumitru46]

Relevant photos, I think.

[alindumitru46]

Bad action

Attachments

[fzabkar]

ICBW, but ISTM that the "FF" in the Err register suggests that the drive could be brain dead. Alternatively, it could just be that the drive does not communicate until it has loaded its firmware.

I would check the crystal and the outputs of each of the supply supervisor ICs. If the crystal is not oscillating, or if one of the supervisors is holding the flash controller in the reset state, then that could explain the symptoms.

BTW, you can use a TSR program called Snarf to capture MHDD screen shots.

Snarf - Tool to capture full-screen DOS graphics :
http://www.hddoracle.com/viewtopic.php?f=36&t=2334&p=15796

[alindumitru46]

Crystal Oscillator is the one I have noted X100 ?!
I do not know what time I have to make measurements today, the lack of time kills me .
Thanks for the suggestion with snarf app, it is very useful and i will put it on all computers. I did not think of doing research for such a solution.

Attachments

[fzabkar]

Crystal Oscillator is the one I have noted X100 ?!

Yes.

Generally speaking, when you troubleshoot a microprocessor based PCB you ...

1/ check the supply voltages
2/ check the crystal oscillator
3/ verify the power-on reset pin(s)

[alindumitru46]

Hi there,
After a long period of convalescence I'm trying to get into activity.
So I managed to check the crystal oscillator marked as X100 and there in no value in Hz scale for the multimeter. The value of voltages measured ​​(pin 2 as ground) are of the mV order (less than 5mV) and bring fast to zero.
The pins are like this:

I did not succeed in identifying its value because the IC does not write anything than LF.

[fzabkar]

X100 appears to be a simple crystal rather than a crystal oscillator. The latter incorporates electronic circuitry wherease the former does not. That said, pins 1 and 3 should be biased at a DC level corresponding to half the supply voltage of the flash controller. Furthermore, I doubt that a multimeter has a frequency range in the tens of MHz. Instead you would need an oscilloscope.

I expect that the circuit looks like this:

Code:

        .-------------------.
        |                   |
        |     .-----.       |
        |     |     |       +------.
        |    ===    |       |      |
        |    GND    |       |     ---
        |         .-----------.   ---
       .-.        | 4   _   3 |    | C182
R134   | |        |    | |  | |    |  10pF
       | |        | .-|| ||-' |   ===
1Mohm  '-'   X100 | |  |_|    |   GND
        |         |o        2 |
        |         '-----------'
        |          1|       |
        '-----------+       |
                    |      ===
                   ---     GND
             C165  ---
             10pF   |
                    |
                   ===
                   GND

[alindumitru46]

Hmmm... it's seems to be game over.
If I am able to use a multimeter, an oscilloscope is beyond the limit that I could reach.
Maybe I can find someone, though ... But that means I have to wait ...
Thanks for your help so far.

[fzabkar]

You could check the outputs of the Voltage Detector ICs. If any are bad, that could cause the controller to remain in the reset state.