This Error can be caused by a bad floppy disk but more often then not the FDD ribbon has been crimped and caused an open with some of the wires within it. To correct this problem you will need to unplug the computer and reinstall a new ribbon that you know is not damaged. Through the years you might notice that this happens a lot and can be caused by carelessness when assembled or was crunched when drives were being installed.
In any case, this problem will occur from time to time and can be very frustrating to the user and the to the person diagnosing the problem.
