Problem with external ext4 HDD

Question

Hi Arch community!
I have an Arch installation on a 40GB IDE hdd, in an old desktop working flawlessly. This morning I removed the hard drive from the computer and put it in an external enclosure to connect it via USB to another PC, also running Arch. However there's now way to access the disk and its partitions using the external enclosure. According to dmesg the disk could be damaged, but to ensure this I placed it back on the old computer and everything works perfect. Arch loads and I can access my files and folders.
I have no idea of the reason of this behaviour. Can you help me??
Here are the dmesg messages:
scsi 6:0:0:0: Direct-Access Maxtor 6 E040L0 0811 PQ: 0 ANSI: 0
sd 6:0:0:0: Attached scsi generic sg1 type 0
usb-storage: device scan complete
sd 6:0:0:0: [sdb] 78165360 512-byte logical blocks: (40.0 GB/37.2 GiB)
sd 6:0:0:0: [sdb] Test WP failed, assume Write Enabled
sd 6:0:0:0: [sdb] Assuming drive cache: write through
sd 6:0:0:0: [sdb] Test WP failed, assume Write Enabled
sd 6:0:0:0: [sdb] Assuming drive cache: write through
sdb: sdb1 sdb2 < sdb5 >
sd 6:0:0:0: [sdb] Test WP failed, assume Write Enabled
sd 6:0:0:0: [sdb] Assuming drive cache: write through
sd 6:0:0:0: [sdb] Attached SCSI disk
usb 1-1: USB disconnect, address 2
sd 6:0:0:0: [sdb] Unhandled error code
sd 6:0:0:0: [sdb] Result: hostbyte=0x07 driverbyte=0x00
sd 6:0:0:0: [sdb] CDB: cdb[0]=0x28: 28 00 00 1f de 41 00 00 40 00
end_request: I/O error, dev sdb, sector 2088513
Buffer I/O error on device sdb5, logical block 0
Buffer I/O error on device sdb5, logical block 1
Buffer I/O error on device sdb5, logical block 2
Buffer I/O error on device sdb5, logical block 3
Buffer I/O error on device sdb5, logical block 4
Buffer I/O error on device sdb5, logical block 5
Buffer I/O error on device sdb5, logical block 6
Buffer I/O error on device sdb5, logical block 7
sd 6:0:0:0: [sdb] Unhandled error code
sd 6:0:0:0: [sdb] Result: hostbyte=0x01 driverbyte=0x00
sd 6:0:0:0: [sdb] CDB: cdb[0]=0x28: 28 00 00 1f de 81 00 00 40 00
end_request: I/O error, dev sdb, sector 2088577
Buffer I/O error on device sdb5, logical block 8
Buffer I/O error on device sdb5, logical block 9
sd 6:0:0:0: [sdb] Unhandled error code
sd 6:0:0:0: [sdb] Result: hostbyte=0x01 driverbyte=0x00
sd 6:0:0:0: [sdb] CDB: cdb[0]=0x28: 28 00 00 1f de c1 00 00 40 00
end_request: I/O error, dev sdb, sector 2088641
and this is the output from parted
GNU Parted 1.9.0
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model: Maxtor 6 E040L0 (scsi)
Disk /dev/sdb: 40.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number Start End Size Type File system Flags
1 32.3kB 1069MB 1069MB primary linux-swap(v1) boot
2 1069MB 40.0GB 38.9GB extended
5 1069MB 40.0GB 38.9GB logical ext3
(parted)
The particion showed above is formatted in ext4 instead of ext3 as Parted displays.
Instead of connecting the enclosure while running Arch on another computer I also tried to boot it up directly using the Grub installed on the disk, and it doesn't even load Grub properly, displaying an Error 18.
I also tried a fsck on the disk but it also failed.
What could I do to access my data via USB without formatting?
Thanks in advance,
Alex.

Answer 1

Just passed testdisk, first looking for superblocks, and then looking for partitions. Here's the output
Ext2 superblock found at sector 32768000 (block=4096000, blocksize=4096)
Linux 130 1 1 4864 254 63 76067712
superblock 32768, blocksize=4096 []
superblock 98304, blocksize=4096 []
superblock 163840, blocksize=4096 []
superblock 229376, blocksize=4096 []
superblock 294912, blocksize=4096 []
superblock 819200, blocksize=4096 []
superblock 884736, blocksize=4096 []
superblock 1605632, blocksize=4096 []
superblock 2654208, blocksize=4096 []
superblock 4096000, blocksize=4096 []
Current partition structure:
1 * Linux Swap 0 1 1 129 254 63 2088387
2 E extended 130 0 1 4864 254 63 76067775
No EXT2, JFS, Reiser, cramfs or XFS marker
5 L Linux 130 1 1 4864 254 63 76067712
5 L Linux 130 1 1 4864 254 63 76067712
And finally the error.
This partition ends after the disk limits. (start=2361681, size=76067712, end=78429392, disk end=78165360)
Disk /dev/sdc - 40 GB / 37 GiB - CHS 4865 255 63
Check the harddisk size: HD jumpers settings, BIOS detection...
The harddisk (40 GB / 37 GiB) seems too small! (< 40 GB / 37 GiB)
The following partition can't be recovered:
Linux 147 2 1 4882 0 63 76067712
EXT3 Large file Sparse superblock Recover, 38 GB / 36 GiB
Parted also displays the following message
Any other idea?