Hello,
I have a Transcend 4GB USB flash drive that suddenly stopped working. However, when I insert it into the USB slot, the light on the drive glows, but I'm unable to mount the drive, neither does ubuntu detect it.

I disconnected the flash drive, and then run `dmesg | tail`. The result was this :

[ 623.940610] scsi7 : SCSI emulation for USB Mass Storage devices
[ 623.940928] usb-storage: device found at 6
[ 623.940931] usb-storage: waiting for device to settle before scanning
[ 628.940422] usb-storage: device scan complete
[ 628.941102] scsi 7:0:0:0: Direct-Access Generic USB Flash Disk 7.76 PQ: 0 ANSI: 2
[ 628.943708] sd 7:0:0:0: [sdb] Attached SCSI removable disk
[ 628.943818] sd 7:0:0:0: Attached scsi generic sg2 type 0
[ 912.480581] CE: hpet increasing min_delta_ns to 22500 nsec
[ 1025.224066] CE: hpet increasing min_delta_ns to 33750 nsec
[ 1294.541827] usb 2-1: USB disconnect, address 6

Then I connected it again and the result of `dmesg | tail` now was :

[ 1294.541827] usb 2-1: USB disconnect, address 6
[ 1300.200578] usb 2-1: new high speed USB device using ehci_hcd and address 7
[ 1300.398678] usb 2-1: configuration #1 chosen from 1 choice
[ 1300.399224] scsi8 : SCSI emulation for USB Mass Storage devices
[ 1300.412323] usb-storage: device found at 7
[ 1300.412327] usb-storage: waiting for device to settle before scanning
[ 1305.412373] usb-storage: device scan complete
[ 1305.413053] scsi 8:0:0:0: Direct-Access Generic USB Flash Disk 7.76 PQ: 0 ANSI: 2
[ 1305.422710] sd 8:0:0:0: [sdb] Attached SCSI removable disk
[ 1305.422822] sd 8:0:0:0: Attached scsi generic sg2 type 0


Can I, by any means, recover this flash drive?

Regards,
Mihir

---
Ubuntu 9.04 Jaunty
HP Pavilion dv6-1152tx, Intel Core2 duo at 2 GHz, 4GB Memory

When it gets a letter
try fdisk -l and look for that drive (sdb in this instance)

then mount /dev/sdb, or mebbe /dev/sdb1 should mount it. You will have to supply a directory to mount it on (e.g. /mnt)

When I try to mount it with mount,

mount /dev/sdb /media/Pendrive

it says

/dev/sdb : unknown device

or

No medium to mount.

Also, I cannot see anything in fdisk -l.

check the o/p of dmesg |tail and wait until it gets a drive letter. You may need to mount sdb1 instead of sdb
fdisk -l
tells you about all partitions on all disks. Read that.

I tried mounting it with `mount /dev/sdb1 /media/Pendrive`; it said "special drive /dev/sdb1 does not exist."

When I mounted a perfectly healthy flash-drive, the output of dmesg | tail was

[ 527.129875] sd 7:0:0:0: [sdc] Write Protect is off
[ 527.129877] sd 7:0:0:0: [sdc] Mode Sense: 00 00 00 00
[ 527.129879] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 527.130874] sd 7:0:0:0: [sdc] 2015232 512-byte hardware sectors: (1.03 GB/984 MiB)
[ 527.131496] sd 7:0:0:0: [sdc] Write Protect is off
[ 527.131498] sd 7:0:0:0: [sdc] Mode Sense: 00 00 00 00
[ 527.131500] sd 7:0:0:0: [sdc] Assuming drive cache: write through
[ 527.131504] sdc:
[ 527.274251] sd 7:0:0:0: [sdc] Attached SCSI removable disk
[ 527.274323] sd 7:0:0:0: Attached scsi generic sg3 type 0

I can't see any message which says anything about hardware sectors on the damaged flash-drive. So, is that drive physically damaged?

Also try it in different USB ports and computers, if it works in none, then it's probably dead, toss it in the garbage because chances of recovery if it is dead are zero.