Cannot access disk, partition table broken

Solution 1:

There are bad sectors at the beginning of the disk, where partition table should be located. And it seems that your attempt to remap them was unsuccessful.

I usually remap bad sectors with MHDD; it's a freeware utility running in DOS, so it can bypass OS cache and work directly with disk controller. Check SMART monitoring data to make sure there are no unremapped bad sectors; if there are some, run MHDD again until there are none.

After all bad sectors are remapped, try repartitioning your HDD in Linux. dd-ing first megabyte with zeroes might be helpful if remainings of old partition table confuse your fdisk.

Another possible cause of your problems might be faulty data cable or too weak power supply; but get rid of bad sectors first.

Also there's such thing as softbads: bad sectors which occur as a result of interrupted write (because of accident power loss or insufficient wattage of power supply); they are usually fixed by disk hardware in place without remapping if that particular sector is rewritten many times in place (as MHDD does).

Solution 2:

Mikhail has the answer to your problem more or less in the bag, but is missing a key point.

If possible, when you cut the power it could messed up the MBR, which like the partition table is located at the beginning of the disk, but if this is somehow corrupted you would need to manually rewrite all 512 bytes of the MBR or attempt to use MBR repair to fix the problem, as you see the last 72 bytes of the MBR are where the partition table is located.

I speak from experience as I will admit, I did the same thing you did and it took me a hell of a long time to figure out exactly what I had done and how to fix it, most problems like this are generally just blown off as hardware failure because most don't want to take the work just to save a hard disk.