Matt, thanks for the great reply. "dd if=/dev/sdN of=/dev/null bs=512 count=1" produced no error. Dmesg reported :
[ 842.633468] usb 5-1: USB disconnect, address 3
[ 846.956017] usb 5-1: new high speed USB device using ehci_hcd and address 5
[ 847.093455] usb 5-1: configuration #1 chosen from 1 choice
[ 847.094812] scsi8 : SCSI emulation for USB Mass Storage devices
[ 847.095755] usb-storage: device found at 5
[ 847.095765] usb-storage: waiting for device to settle before scanning
[ 852.092605] usb-storage: device scan complete
[ 852.093690] scsi 8:0:0:0: Direct-Access LEXAR JD FIREFLY 1100 PQ: 0 ANSI: 0 CCS
[ 852.097287] sd 8:0:0:0: [sdb] 3932160 512-byte hardware sectors (2013 MB)
[ 852.098169] sd 8:0:0:0: [sdb] Write Protect is off
[ 852.098181] sd 8:0:0:0: [sdb] Mode Sense: 43 00 00 00
[ 852.098187] sd 8:0:0:0: [sdb] Assuming drive cache: write through
[ 852.100540] sd 8:0:0:0: [sdb] 3932160 512-byte hardware sectors (2013 MB)
[ 852.101411] sd 8:0:0:0: [sdb] Write Protect is off
[ 852.101417] sd 8:0:0:0: [sdb] Mode Sense: 43 00 00 00
[ 852.101423] sd 8:0:0:0: [sdb] Assuming drive cache: write through
[ 852.101432] sdb:
[ 852.163712] sd 8:0:0:0: [sdb] Attached SCSI removable disk
[ 852.164313] sd 8:0:0:0: Attached scsi generic sg2 type 0
So I tried dd if=/dev/sdN of=/home/usb bs=512 count=3932160 and got no errors, so the hardware is fine.
I could not get dd_rescue to work.
I decided that the MBR must be corrupted, so I downloaded an MBR replacer for USB drives. It ran without error, but the flash drive still shows as blank with no file system. I am guessing that what I need next is an MBR editor that will allow me to report the 2MB VFAT32 file system again without reformatting and losing all the data. I think the device would work fine again if I just let QTParted rebuild the partition table and format, but I would like to try and save the data first.
Mike
If "dd if=/dev/sdN of=/dev/null bs=512 count=1" returns errors, then
you've probably got serious hardware problems. You could try using
dd_rescue to make a copy of the disk, but I wouldn't hold out too
much hope for that. Whatever you do, turn off any automounter
thing, because it'll do stupid things when presented with a failing
disk. When you plug the drive in, what does dmesg say about the
drive? Reproduce those messages for us.
--
Matt G / Dances With Crows
The Crow202 Blog: http://crow202.org/wordpress/
There is no Darkness in Eternity/But only Light too dim for us to see