SD card failure, can't read superblock
Looks like Ubuntu is getting confused and trying to mount it as an ext3/4 filesystem (which have superblocks). You might want to try mounting it explicitly as vfat.
mount -t vfat /dev/sdb1 /your_mount_point_for_SD_cards
HOWEVER, I'm guessing something has actually corrupted the thing. If it shows up in your device table at all (ls /dev/sdb*) then you might be able to see if it's still readable with the dd command. something like "dd if=/dev/sdb1 bs=1024k count=10 | less" should give you an idea if it's readable. Even if readable, the ability to reconstruct previous files is questionable.
You could also try mounting it on another computer but that's a long shot.
I too had this issue with my mobile's SD card and I was unable to browse it from both Ubuntu and Windows. The partition was FAT32 so I was hopeful to get it fixed via Windows.
I ran following command in CMD to get it working again:
CHKDSK f: /F /V /R /X
Note: f:
was the path of my SD card.
Excerpt from Microsoft's website about the CHKDSK
command:
The complete syntax for Check Disk is as follows:
CHKDSK [volume[[path]filename]] [/F] [/V] [/R] [/X] [/I] [/C] [/L[:size]]
The options and switches for Check Disk are used as follows: volume Sets the volume to work with path/filename Specifies files to check for fragmentation (FAT16 and FAT32 only)
/F Fixes errors on the disk
/V Displays the full path and name of every file on the disk (FAT16 and FAT32); displays cleanup messages if any (NTFS)
/R Locates bad sectors and recovers readable information (implies /F)
/X Forces the volume to dismount first if necessary (implies /F)
/I Performs a minimum check of index entries (NTFS only)
/C Skips checking of cycles within the folder structure (NTFS only)
/L:size Sets the log file size (NTFS only)
/B Re-evaluates bad clusters on the volume (NTFS only; implies /R)