Electronic Testing help needed

[hhddrec]

Hi gurus!

Can you help me on USB pendrive testing?

When i plug usb on my computer the LED blinks for about 5 secs, the penDrive is recognized by Windows but no acces to media.

Any help apreciated.

Attachments

[lcoughey]

The controller is likely gone stupid. You will need flash recovery tools where you can remove the chips, get dumps and then virtually reproduce the controller and recover the data. If you don't have the tools already (which I am assuming based on this post), you should consider outsourcing to a lab that can help you.

Unless I'm missing something, this should be a relatively straight forward recovery for us.

[fzabkar]

The only simple tests I can think of would be to measure the voltage across the 2R2 resistor. That will tell you the current draw of the pen drive.

Another test would be to measure the voltage across the capacitors. There should be +3.3V for the NAND flash.

Also check the zero-ohm resistors.

[HaQue]

Likely not an electrical issue. I agree with Luke.

You can try and take an image of the disk and the case of the partitioning/filesystem being messed up, this should work.
Follow the instructions I gave in my second post from here:

http://forum.hddguru.com/viewtopic.php?f=10&t=29110

key points, insert your drive but don't click off any windows messages or do anything else apart from the steps..

I think it is a controller firmware/firmware parameter corruption issue. Some of the Parameter of the USB firmware relate to the NAND flash chips properties. if some of these parts are corrupt, the controller can't talk the flash chip, which is where the data is. Other times it is basically disk partition or FAT information that is messed up and you can recover fairly easily.

[hhddrec]

The controller is likely gone stupid. You will need flash recovery tools where you can remove the chips, get dumps and then virtually reproduce the controller and recover the data. If you don't have the tools already (which I am assuming based on this post), you should consider outsourcing to a lab that can help you.

Unless I'm missing something, this should be a relatively straight forward recovery for us.

Hi Luke and HaQue;

Thanks, yes very problably bad controler IC
I got SOFT-CENTER tools, but id like to test it, for knowledge

[hhddrec]

The only simple tests I can think of would be to measure the voltage across the 2R2 resistor. That will tell you the current draw of the pen drive.

Another test would be to measure the voltage across the capacitors. There should be +3.3V for the NAND flash.

Also check the zero-ohm resistors.

Thanks Fran;
i'll test it and report here

[HaQue]

IMHO, the knowledge of the values of the drive are not going to be that useful for you without the background knowledge of what each components role and effect on the circuit is.

There are quite a few configurations of flash circuits. Yes most have a similar few caps or resistors, but unless you can look at a different circuit, and say that across this set of points, I expect this value.. then I don't think it is the appropriate spenditure of time.

Maybe better would be a couple of hours reading about capacitors, resistors xtals etc and their effects, and looking at some schematics. I am not saying looking at flash circuits is not valuable, just that the method might not be optimal.

Good Luck

[hhddrec]

measure the voltage across the 2R2 resistor

2r2 ???
maybe 2R7 ?

[fzabkar]

Yes, sorry. I meant 2R7.

BTW, I agree with everyone else that the problem is most likely not an electronic one. I'm just responding to your thread as per your private request.

[hhddrec]

Yes, sorry. I meant 2R7.

BTW, I agree with everyone else that the problem is most likely not an electronic one. I'm just responding to your thread as per your private request.

So many Thanks Fran