Walter, I was working on a mid-2007 IMac (2133) and found your instructions helpful but not always complete or right. I have added some comments in some of the steps to clarify.
Robert, how did you install the OS on the new drive? I have a bootable OSX El Capitan on a flash drive, but when I turned on the Imac holding down the option key the IMac would not go beyond a white screen. Any suggestions based on your experience. I am also replacing the 320GB with a 500 SSD.
I need some advice about replacing a 320GB HD with a 500 SSD for my Imac mid-2007. The SSD drive doesn’t require a thermal sensor. What do you do with the sensor that is attached to the original HD? Do you reconnect it and tape it back on the body of the SSD drive?
I have made a bootable OSX El Capitan Flash Drive. What is the sequence for formatting and getting the SSD drive loaded with OSX EL Capitan? Does one plug in the Flash Drive and start the IMac holding the Option key?
I would be grateful for experienced advice.