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)