Hi [NAME],   Can you confirm that the server is R730 or R730XD? As R730, it has no capability to install flex bay at the rear. [URL]   If it's R730XD, the failed drive might be inside the chassis which blink does not work. Can you try opening the chassis cover to check for any internal drives. 
We have a Dell PowerEdge R730 and the hard drive 0:1:17 has failed. I am unable to determine the drive bay it is in. There are 14 drive bays on the front and 2 on the back. I tried Dell Open Manage to make it blink, but do not see any drives blinking. During POST the message 1 virtual drive partially degraded displays.  Any ideas?
Poweredge drive failure 0:1:17