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-   -   USB Flash Drive "unreadable" (http://www.linuxquestions.org/questions/linux-hardware-18/usb-flash-drive-unreadable-616100/)

willrs2 01-24-2008 04:43 PM

USB Flash Drive "unreadable"
 
I have a flash drive (512 MB Sandisk U3) that won't work. On windows, when I plug it in, the light flashes like normal, but when I try to access the M: drive that just appeared, it says to insert a device. In linux (backtrack2), it flashes and stuff, but konqueror doesn't recognize it. When I start qtparted, it recognizes it as /dev/sdc, but when I try to write a new table, it says it can't. Oh, yea, if you haven't noticed, I don't care if the data is erased. There wasn't anything important on it.

michaelk 01-24-2008 05:27 PM

Is this a stock U3 device or did you remove the launchpad stuff?

Did it ever work correctly in windows? If it is a stock U3 flash disk then 2 devices should pop up. i.e a CD device and a normal drive device. Since it doesn't work in either OS the disk might be faulty.

willrs2 01-24-2008 05:59 PM

Yes it is a stock U3 device and yes, two drives open, and no, I haven't removed it on THIS one (I removed it from another one to be replaced with PortableApps). The "CD" drive launches correctly, including the software on the "drive," but the other drive doesn't open at all. I'm better with windows XP than I am at linux, so here's some more information: When I go to the disk management utility, the drive shows up correctly, but it says the status is unreadable. The disk management utility also says that the partition style is Master Boot Record (MBR), and the capacity is 0 MB. PC Inspector Smart Recovery, though says that it is around 487 MB, which is correct. It was able to scan and locate all the sectors (there were a lot). That gave me a reason to believe that it isn't a hardware problem.

michaelk 01-24-2008 06:42 PM

It is difficult to tell what is going on. I do not know the inner workings of the drive to say whether you can write a new table or not. Could be a driver issue in windows. linux, have you tried mounting the drive manually?

dracolich 01-24-2008 07:59 PM

I wonder if the partition table or mbr got screwed up. Have you removed it without unmounting it first? Or in Windows, removed it without stopping it via the system tray icon? Did you have it since it was new and this just happened? Or did you get it from someone else already in this condition?

Since you've already said you don't care about any existing data, and you're still more comfortable in Windows, you're best bet is probably to download Sandisk's format utility for flash drives to try to restore the partition.

http://www.sandisk.com/OEM/ProductCa...sh_Drives.aspx

willrs2 01-24-2008 09:14 PM

In linux, I have tried to mount it manually, and it mounts just fine. The partition manager (qtparted) recognizes it, but is, for some reason, not able to create a new table on the drive.

I'm doing this as a favor for one of my friends, so I don't know exactly what he has done with it. But... this is his "policy": If the light is blinking, don't remove it, if it isn't it's safe to remove. Neither him nor I use the "Safely Remove Hardware" thing in Windows, he never uses linux, and I sometimes unmount it in linux. I have the same exact flash drive, except a different size, 4GB instead of 512MB. If you need to know, this is his exact flash drive:
http://sandisk.com/Products/Item(191...2MB_Black.aspx.

About the sandisk utility. It didn't detect the drive at all. The strange thing is, the virtual cd drive created by the U3 starts up the U3 splash screen, but says that the drive (M:) is unreachable (or something like that).

By the way, the light always stays lit when it's plugged in. I also have two other computers besides this (XP Pro) one. One is a Vista Home Premium (very new, 3 months) and one is a regular Windows XP (fairly old, 6 years). Mine is going on it's second year. I dual book windows XP Pro and Backtrack2.

dracolich 01-26-2008 11:03 AM

Quote:

Originally Posted by willrs2 (Post 3034430)
In linux, I have tried to mount it manually, and it mounts just fine. The partition manager (qtparted) recognizes it, but is, for some reason, not able to create a new table on the drive.

I'm doing this as a favor for one of my friends, so I don't know exactly what he has done with it. But... this is his "policy": If the light is blinking, don't remove it, if it isn't it's safe to remove. Neither him nor I use the "Safely Remove Hardware" thing in Windows, he never uses linux, and I sometimes unmount it in linux. I have the same exact flash drive, except a different size, 4GB instead of 512MB. If you need to know, this is his exact flash drive:
http://sandisk.com/Products/Item(191...2MB_Black.aspx.

About the sandisk utility. It didn't detect the drive at all. The strange thing is, the virtual cd drive created by the U3 starts up the U3 splash screen, but says that the drive (M:) is unreachable (or something like that).

By the way, the light always stays lit when it's plugged in. I also have two other computers besides this (XP Pro) one. One is a Vista Home Premium (very new, 3 months) and one is a regular Windows XP (fairly old, 6 years). Mine is going on it's second year. I dual book windows XP Pro and Backtrack2.

I have the same 512MB model and it's normal for the light to stay on. It only blinks to indicate activity. You say Neither him nor I use the "Safely Remove Hardware" thing in Windows...and I sometimes unmount it in linux and I think that's the problem. I see flash drive problems quite often due to this. Mostly just data loss, though. Since the Sandisk utility failed I would start thinking about a replacement.

Have you tried formatting it from Disk Manager? Or in Linux try this, assuming it detects as sdc and the corrupt partition is sdc2:
First check dmesg output to make sure it's detected and find the right device name. Something like sdc2 with 497MB, or if Disk Manager is right it'll be sdc2 with 0MB. If it's not detected this won't work. Use dd, with the disk connected but unmounted, to wipe the entire partition.
Code:

dd if=/dev/zero of=/dev/sdc2
and wait for it to finish. It should take a minute or two to run on 497MB in USB2. Then use something like fdisk or cfdisk to create a new vfat partition.
Code:

cfdisk /dev/sdc
And finally mkfs or Windows to format it.

If none of that works I might suspect the device's firmware has become damaged.

Good luck.


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