My external hdd with a single NTFS partition was accidentaly plugged out (kids!)... and is now corrupted.

Iv tried running ntfsfix - with no luck - output below..

When I look at the disk under disk management in Windows 7 it shows up as having 5 partitions 2 of which are unallocated - none have drive letters and it is not possible to set any (that option and most others are greyed out) - so I can't run chkdsk /f

Iv tried using Minitool partition wizard which was mentioned as a solution to another similar question here. It showed the whole drive as one partition, but as unallocated, and the option -- "Check File System" was greyout.

Is there anything else I could try ?

Output of fdisk -l

    Disk /dev/sdb: 1500.3 GB, 1500299395072 bytes
    255 heads, 63 sectors/track, 182401 cylinders, total 2930272256 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytest 
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disk identifier: 0x69205244

    This doesn't look like a partition table
    Probably you selected the wrong device.

       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1   ?   218129509  1920119918   850995205   72  Unknown
    /dev/sdb2   ?   729050177  1273024900   271987362   74  Unknown
    /dev/sdb3   ?   168653938   168653938           0   65  Novell Netware 386
    /dev/sdb4      2692939776  2692991410       25817+   0  Empty

    Partition table entries are not in disk order

Output of ntfsfix

me@vaio:/dev$ sudo ntfsfix /dev/sdb
Mounting volume... ntfs_mst_post_read_fixup_warn: magic: 0xffffffff  size: 1024   usa_ofs: 65535  usa_count: 65534: Invalid argument
Record 0 has no FILE magic (0xffffffff)
Failed to load $MFT: Input/output error
FAILED
Attempting to correct errors... ntfs_mst_post_read_fixup_warn: magic: 0xffffffff  size: 1024   usa_ofs: 65535  usa_count: 65534: Invalid argument
Record 0 has no FILE magic (0xffffffff)
Failed to load $MFT: Input/output error
FAILED
Failed to startup volume: Input/output error
Checking for self-located MFT segment... ntfs_mst_post_read_fixup_warn: magic: 0xffffffff  size: 1024   usa_ofs: 65535  usa_count: 65534: Invalid argument
OK
ntfs_mst_post_read_fixup_warn: magic: 0xffffffff  size: 1024   usa_ofs: 65535  usa_count: 65534: Invalid argument
Record 0 has no FILE magic (0xffffffff)
Failed to load $MFT: Input/output error
Volume is corrupt. You should run chkdsk.

Options available with MiniTool:

Related questions:

How to fix a damaged/corrupted NTFS filesystem/partition without losing the data on it?

Repair corrupted NTFS File System