I have a 2011 iMac whose drive has failed but the data can be recovered per the Genius Bar at Apple. To retrieve data I want to use my old Mac Mini. I have a fire wire 400 connected to the Mac Mini (host) and a converter (800) plugged into the other end the iMac for Target Disk Mode (TDM). When I hold down the T key on the TDM the symbol comes up and is moving on the screen. When I start the Mac Mini, host, I do not see the TDM on the desk top. What are the steps I need to go through in order for the Host to recognize the TDM drive? Any help would be appreciated.