Sorry for the typo, the unit is 12,2. I am aware of the heat sensor issue, will order the heat sensor kit from OWC as soon as I determine if the drive is really bad. The computer boots to a black screen that says "bootable device: insert boot disk and press any key". So I think the original owner may have a wiped the drive improperly and when they tried to re-install OS X, there was junk left on the hard drive that wasn't erased and it generated error messages....or worst case scenario the drive has crapped out!
I have a retail OS X.6 that I purchased from the Apple Store, I have OS X.10.11 on a USB drive, so I have several options to install the OS, including doing a internet recovery of the original shipped OS.
I so intend to thoroughly check the drive out with all the available OS tools and the manufacturer's tools.
Thanks for your comments and observations....a second pair of eyes is always good!
[doublepost=1489241193][/doublepost]After I address the hard drive issues and have the machine up and running, I intend to install a Samsung EVO SSD under the optical drive with a kit from OWC. I will use the SSD for the OS boot drive for both OS X.10.11 or 10.12 and Windows 10.
I have a retail copy of VM Fusion 8.5 which apparently is the easiest, fastest and most reliable way to run Windows applications on a Mac...at least that is what they claim!