Review on OWC 4.0TB HDD Upgrade Kit for 2009-2010 iMacs - Includes Thermal Sensor, Tools, and 4.0TB Hard Drive by Terrance Singletary

I have tried to install exactly as described in the videos for my 2009 desktop but I keep getting a white screen with a folder of files and a question mark. I'm trying to mount the drive to see if I need to reformat it and despite all the troubleshooting, buying new external mounting cables etc. I can't see the drive on any of my computers at all. I'm wondering if I have a defect or if it's no longer compatible with these models and it's been frustrating to find out for weeks - now this week I'm waiting to call support to find out and update. Wouldn't recommend buying at this point.