SanDisk SSD Plus - really bad reading

[melvin]

Hello,
Maybe someone has an idea how to improve reading rate from this drive. When plugged it stays BSY. Uploading loader + translator creation i get access to sectors. But it reads with a lot of errors at 100-300KB/s - image attached. I tried with and without ECC, at different speeds. Tried cooling it... it always work the same. So any tips what may help are more then welcome.

Attachments

[lcoughey]

That is 1000 times better than the one I'm working with. After 2 full passes, I've only read about 70,000,000 of 500,000,000 sectors green...the rest are black.

[melvin]

So we both are not gonna get paid... I'm "lucky" that i need only like 100MB of data, just small files, but MFT is 2GB, i have half of it, and maybe 40% od good sectors belonging to the data i need. Reread x200, multiple passes and just a few sectors more are good. Some sectors can be easily fixed manualy but not milions of them :/

Did you find any way that made any difference?

[lcoughey]

Freezing with compress air - nothing
Heating with heat gun - nothing
Reflow - nothing
Reporting - nothing

[pcn]

I have the same bad experience with these SSDs based on SM-Controllers and nothing seems to help. I was told the problem is that no read retry command is supported and the only thing that might help is heating and reread until you get out the missing lbas. But that also does not help in most cases (I had) and getting a good result would take years

[melvin]

Yes, those controllers are terrible. In most crucial files with few sectors missing i found autoclicker really helpful.

[ddrecovery]

I did have one a while ago but didn't need too much data, just some QB files, I did over 100 passes before I got a repairable file. Reading quality does improve with each pass, but it is really SLOW....

[melvin]

I found a manual method to read some more of those sectors by using autoclicker. Can be done if there is 100 of missing sectors but not with 20 000 000. Now i'm thinking if there is any way to make it more automatic. A script or something to open those dark green sectors with ECC errors and click 1000 times "load" button. It works quite nice. From 1 second to 5 minutes and i got most sectors i tried it with read.

[fzabkar]

ISTM that one possible approach would be to adjust the NAND Vcc/Vccq supplies in-circuit. That is, apply the same tweaks that you would normally do when performing a "chip-off" read.

[melvin]

That is a good idea! Will check if PC-3000 will accept another power supply.
Just recovered 0,6MB over 5 hours...

Last edited by melvin on July 7th, 2018, 18:38, edited 1 time in total.

[ddrecovery]

That is a good idea! Will check if PC-3000 will accept another power supply.

AFAIK you cannot alter the power supply via the PCIe board, but you can alter the power out of the new terminal 3 adapter.

[fzabkar]

I'm not suggesting that anyone play with the external supply. That would serve no purpose. Instead I'm suggesting that we locate the onboard NAND supply voltages and make minor modifications to the circuit. If these voltages are set by resistive potential dividers, then the mods should be relatively easy.

[fzabkar]

If you can't modify the regulator's output voltage, then disconnect it and patch an external regulator into the circuit. Something like this ...

Repair of Plextor SSD PCB:
https://www.eevblog.com/forum/repair/repair-of-plextor-ssd-pcb/