have you tried my idea, or pulling the 3-pin power supply off the bad block?  It should shut that core down, and thus revitalizing the good core remaining on that board.

FYI, I have now one machine with only 3 water blocks connected (one core with no water block, waiting for the new block to arrive tonight).  And it is hashing nicely with 12 chips, 4 at rest because of the lack of any water cooling system connected to it, not even the power connected.

Try this