FLEX 6300 6500 6700 fans

OOOPPs One (1) pair.

I bought a couple of fans a few years ago and was getting tired of the 600hz fan noise so tonight I opened up the 6700 for the first time and started to replace the fans. The one on the right no problem however while removing the left fan the whole heatskink including the metal part stamped VERTEX-6 came off. It looks like it was held on with a drop of what I assume is glue on each of the four corners. see included pictures. Does anyone know what type of glue or what substance that is? What little of it remaining is basically powdery so it must have deteriorate over time. I'm hoping just a small, small dab on each corner remount VERTEX-6 heatsink, let dry for a few hours then mount the fan/heatsink back and were back in business. I applied some thermal dielectric compound as what there was dried. Perhaps to use a different heatsink compound that is also an adhesive?

Hey Mike,,it seems you took things apart further than I though you have to. I thought all you had to do is remove the heat sink from the chip witch I understand is not very easy and dangerus. But you also removed it from the board? Is it glued on there as well? And how is it going now? Finished?

The first fan was replaced with no issue but as I was unscrewing the 4 screws that hold the 2nd fan to the heatsink, the heatsink came off. I was able to contact Xilinx via their forums and they were kind enough to get the specs on the adhesive, which is basically "Thermal Conductive Silicone Plaster Viscous Adhesive Compound Cooling Glue for LED GPU Chipset Heatsink " Ordered it and very carefully put a small drop of adhesive at the four corners and remounted the heatsink. All is good.