Slight twist on the non-recognition problem

My almost brand new iMac will not recognize my brand new 3 TB My Book Essential after I reboot my machine. However, If I then unplug and re-plug the Essential  into the back of the iMac the computer will recognize the drive.

I have reformatted the drive as per instructions, and once it is recognized by the computer, it works fine.

Can anybody shed any light on this? It’s an annoying problem and I fear that it may be a small symptom of a bigger problem.

Many thanks in advance for your help.

Dedlock

could be a driver issue…

download the turbo drivers

which os are you using on the iMac?  what partition scheme did you format the drive in?