I'm afraid you have little chance with your disk. I guess the fact that there is no partition devices means your partition table is lost. Do you know where your partitions start and end? What kind of partitions were they? If they were ext2/ext3, you could use e2tools to read the disk without mount it.
May be the kernel does not access the disk because the bios did report the disk as bad; try to disable the smart option of the bios to see if the partitions reappear.
I would suggest you comment your hdc mount entries on the /etc/fstab before turn on the disk to reduce the disk access to the minimum because the next access can be the last.
The e2tools has the common commands cp, ls prefixed by "e2", e2cp, e2ls, etc. You will use the device to reference the file system, for example:
for the root of the file system.
But all I am talking depends on have the partitions and they are ext2/ext3.