Hello Marco,   I don't suspect you are the cause of the issue.  Leaving the drive in until replacement is to properly maintain airflow for cooling.   Did you replace it with a Dell branded  EQL drive?  Non Dell drives won't work.  Are there any messages in the EQL GUI event viewer when you insert the new drive?  If you are using a proper Dell drive, do you have another spare showing up in that member?    If so, swap the new drive with the spare, and put the spare in the open slot.   Do they both show up?    If not, then sounds like you could be running and older version of the firmware.   During a quite period, try failing over the array.  See if the drives show up then.   You could also open a support case and Dell will help you triage this.   Regards,   Don 
Hi all, few days ago I found a disk fail on my PS4100. I have a new disk but I can't  add it to the system because I did a stupid mistake. I exctracted the disk more than 1 hour so the system put the slot off/empty and now no disk are recognized. Any suggestions ? Thanks a lot. Marco
PS4100 disk replacement