I cannot format a corrupted Sandisk SDHC ULTRA 32Gb micro card. So I used gparted in an Ubuntu system. I deleted the partition (/dev/sdf1), recreated it and formatted it in fat32. It still keeps its original label and 24% used space.
sudo parted /dev/sdf1 unit s print
Model: Unknown (unknown)
Disk /dev/sdf1: 62325760s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
sudo fdisk -l -u /dev/sdf
Disk /dev/sdf: 31.9 GB, 31914983424 bytes 255 heads, 63 sectors/track, 3880 cylinders, total 62333952 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdf1 * 8192 62333951 31162880 c W95 FAT32 (LBA)
sudo dd if=/dev/zero of=/dev/sdf bs=512 count=1
1+0 records in
1+0 records out 512 bytes (512 B) copied, 0.0122556 s, 41.8 kB/s
sudo shred -vzn 0 /dev/sdf
sudo fsck -a /dev/sdf1
fsck from util-linux 2.20.1
dosfsck 3.0.12, 29 Oct 2011, FAT32, LFN
There are differences between boot sector and its backup.
Differences: (offset:original/backup) 71:33/4e, 72:32/4f, 73:47/20, 74:42/4e, 75:5f/41, 76:47/4d, 77:4f/45 , 78:50/20, 79:4c/20, 80:55/20, 81:53/20
Not automatically fixing this.
Orphaned long file name part"173GOPRO"
Free cluster summary wrong (813022 vs. really 744969)
/dev/sdf1: 417 files, 228615/973584 clusters
sudo mkfs.vfat -I /dev/sdf
mkfs.vfat 3.0.12 (29 Oct 2011)
After that, refresh gparted devices takes a long time to display them. Nothing has changed.
Here's where appears the 'overlapping' info
As suggested in an answer by burlian.vlastimil I tried
$ sudo parted /dev/sda unit s print
Error: Can't have overlapping partitions.
but as you can see above I did not get this error msg for my sdf unit
So, I'm stucked at this point.
Edit 1: in my Mac the card is recognized and it displays the tree of directories and files, correct file sizes and dates. Before trying anything I described before I could recover some jpgs I needed so I don't care to lose everything
Edit 2: Added some screenshots from testdisk /log