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Strange Problems with Pendrives


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I accidentally gave the number of sectors in hex. It should have been 30784 or a little less than 16MB.

....

Try SCANDISK again. If you don't want to make changes, use "ignore" to go to the next step after each error.

Ran ScanDisk again, got same error, chose to Ignore. After that, ScanDisk finishes normally:

scan98results.jpg

It seems that ScanDisk is seeing the correct amount of used space, however, the exact same incorrect value is still displayed in the "Properties" tab in Explorer.

Do you need me to image the first 16mb of the disk?

I can't advice to do that. See my exeperience at the beginning of this thread. Now I can't access my pendrive anymore !

Roger

Don't worry, the drive we're working on now is brand new and blank. This one's all for science, haha :thumbup

So maybe we can get to the bottom of these bizarre flash drive errors. I'm beginning to think that the first thing to do afte buying a new one is to repartition it and reformat it, so that way you know it will have "normal" settings :wacko:

I deliberately changed the available space setting in a FAT32 Partition and let SCANDISK run. It reported the same Error as you have seen. I don't think SCANDISK is looking at your MBR which has it's own problems.

If you can Hexedit your image and write it back to your Flash Drive, the following should fix the problem:

Offset 183E8H change F7 to F8

Offset 18FE8H change F7 to F8

These offsets are relative to the MBR.

You only need a 128K Image starting from the MBR.

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@rloew, jaclaz, dencorso:

Are there any more tests that we need to run on the 8GB drive, or any other information to be gathered from it for future reference?

If not, I think I will repartition and reformat it using the method that dencorso suggested, I prefer the idea of having a DOS type boot sector instead of a NTLDR one, and this will hopefully also correct the odd CHS/LBA values. I've Hex-Edited maybe 2 files, so I don't quite trust myself yet to try fixing the partition that way.

IMHO, Considering the odd partition values exhibited by both of my Kingstons, I believe that we should recommend repartitioning & reformatting new flash drives somewhere in the threads dealing with NUSB and/or other USB driver stacks. I know this is not really an option for those who already have data on their flash drives, but it might save some people with new ones from the problems that have been documented here. What are your thoughts?

Edited by LoneCrusader
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I'm satisfied, by now. The reason for the problem you have has been found. So I, for one, agree. It's time to repartition, reformat and put it to use. and yes, that problem will be resolved by repartitioning and reformatting.

So here go some comments on RPM:

1) When you run it in a DOS Box, after you say OK to its dire red warning about being unsafe to be used in Windows, you'll see this kind of display:

part.gif

2) Then (still with no pendrive attatched) circulate once through all the HDDs, using <F5>, to see how it presents your HDDs. Then hit <Esc> to quit and dismiss the DOS Box.

3) Attach the pendrive, wait for it to be displayed in Windows Explorer, copy a smal file to it (whatever file) just to cause it to be added to the device list, Close the Win Explorer, run again RPM, circle again through the HDDs and bingo, you'll see one new drive present. It's quite common that RPM barks at the current partitioning and complains that there is a partition in the pendrive that overlaps something. Don't worry, hit OK, and it'll then present you an HDD with no defined partitions, because it is ignoring what it considers wrong (but the current format and partitioning still are in the pendrive, because you did not write anything to it, just yet). Because of your previous tour without the pendrive, you'll now recognize everyone of your drives and be sure which is the new one (= your pendrive).

4) As soon as you're satisfied everything is making sense, start partitioning.

5) Use only version 240, while you're still getting used to RPM.

Good luck!

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@rloew, jaclaz, dencorso:

Are there any more tests that we need to run on the 8GB drive, or any other information to be gathered from it for future reference?

If not, I think I will repartition and reformat it using the method that dencorso suggested, I prefer the idea of having a DOS type boot sector instead of a NTLDR one, and this will hopefully also correct the odd CHS/LBA values. I've Hex-Edited maybe 2 files, so I don't quite trust myself yet to try fixing the partition that way.

IMHO, Considering the odd partition values exhibited by both of my Kingstons, I believe that we should recommend repartitioning & reformatting new flash drives somewhere in the threads dealing with NUSB and/or other USB driver stacks. I know this is not really an option for those who already have data on their flash drives, but it might save some people with new ones from the problems that have been documented here. What are your thoughts?

My experience has been that new Flash Drives are not bootable and often unrecognizeable by the BIOSes in my Computers. So I repartition and reformat them before putting data on them, using Programs I have written.

Some Flash Drives come with software already on them so people may want to check and retrieve the files before repartitioning.

I have not tried RPM but I wrote my Partitioning Program to be able to rebuild Partitions without losing existing data on the Drive. This would be a solution for people who already have data on their Flash Drives.

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Over the time a few apps have been developed to allow better chances of "universal" booting from USB.

RPM is allright, of course, guess what I was using at the time?:

http://home.graffiti.net/jaclaz:graffiti.n...B/USBstick.html

but why not tring the newer apps:

http://www.boot-land.net/forums/index.php?showtopic=9460

RMPREPUSB or BOOTICE allow, besides "plain" (and "balanced" CHS/LBA partitioning) some more "tricks" that may come as useful, including the "ZIP-like" formatting.

jaclaz

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