Heat sink detached 2008 Max Pro Logic Board

I opened my 2008 Mac Pro for dust removal and noticed that a large (2 1/2 inches x 1 1/2 inches) black heat sink was laying on the left end of my video card. The heat sink apparently fell off a logic board component located to the left of the four PCI slots. There are two chrome plated spring clips attached to the heat sink. I located a photograph of a 2008 Mac Pro logic board that shows the heat sink being attached to the logic board in which the chrome clips appear to hook into the logic board. My logic board appears to have only one of the two necessary hooks so I don't know how to reattach the heat sink. I have owned the computer since new and it has been in the shop only once about a year ago for some sort of logic board service. Since I have not had the machine open, I assume the heat sink sink fell off during service. I use the computer for 8 ton 10 hours daily and it runs fine with no apparant overheating. Can anyone identify the component?

Thanks

Heat sink detached 2008 Mac Pro Logic Board

Thanks for the input. Given the tight space surrounding the logic board I would feel more comtortable using an adhesive tape product rather than the epoxy. It will difficoult to hold the heat sink in place while the epoxy sets as well as the possibility of excess epoxy causing problems. I assume that the tape product will hold the heat sink in place immediately upon placement.
I searched the web and found a line of thermal adhesive tapes made by 3M Company. There are several thicknesses and several thermal conductivity to choose from. Any suggestions? The heat sink and matting surface of the chip are covered with silver paste which is soft. What type of solvent would be good for removal of the base.
What is the functiion of the "southbridge" component? Since mine southbridge may have been running all day, everyday for over a year without the heat sink I wonder what damage way already have occurred? I don'tunderstand how the heat sink became detached. I can see the one loop on my logic board which would have held one of the clips but thee is no sign of the other loop. I would if the technician broke off the loop while servicing the logic board. Anyway what is done is done so now I need to reinstall the heat sink.
Thanks

Heat Sink detached 2008 Mac Pro Logic Board

The 2006 photo shows the same setup as my 2008. Although the heat sink is rather larger (1 1/2 x 2 1/2) the actual contact area cover ed with silver paste is only 1 square inch.Although I have not yet been able to locate a source of small quantities of 3M tape, there are sources fora variety heat sink assemblies including tape but none are my size. Thanks for the alcohol cleaning tip 0 now all I need is the tape. I wonder if the epoxy heaat transfer materials are quick setting. I could probably hold the heat sink in place for a couple minutes. I have not experience any disc problems so maybe I have been lucky.
Thanks

Heat sink detached 2008 Mac Pro Logic Board

Thanks for the links. Artic Silver makes both analumina ceramic thermal adhesive and a silver thermal adhesive. The curing times seem similar - like an hour. What are the differences for the South Bridge application? In reading the forums, it seems that the thermal tape products can also be difficult to work with - especiaaly removal of the backing paper. Do you have any experience with the 3M tape product? I really am concerned about maintaining good contact pressure during the hour curing time of the epoxy. There is no way to use clamps and the original spring clips will not work.

Heat sink detached 2008 Mac Pro Logic Board

Thanks to my forum friends I was able to reattach the heat sink to my Southbridge. I ended up using the ceramic epoxy Artic Product. Although I was able to locate 2 inch squares of the 3M thermal conductive adhesive tape, it seemed that proper positioning the heat sink with tape would more difficult.
Thanks again for the help
Phil Lindsay