I have read all your analysis and proposed solutions to the problem but it seems you still have the fault persisting. I am tempted to believe that K: drive is corrupted and you can check this with this command: “chkdsk K:”
If you check and there’s corruption on the K: drive, then that’s the cause of the alarm not ceasing. However, when you discover it to be corruption, then you should clean it by following a special procedure.
Hope this helps.