Hello,   If you had support I would say upgrade the array firmware and see if that resolves it.    One last suggestion.  Power off array.  Put in one of the drives, remove the active controller, then power on.  If that fails, shutdown, power off, try the other controller.  Make sure passive is removed.   Regards, Don  
I have an older array that I purchased from a defunct company.  A few of the drives have failed and I would like to replace a few of the failed drives. I attempted with just the same model number and it reported that the drive was not supported now I am attempting to replace dell equallogic drives hower there now appears to be a F/W mismatch.  Any thoughts on what drive fw's will match with the equallogic PS6100E.  Thanks 
Equal Logic PS6100E Valid firmwares for the drives themselves