I just built an AMD2800+ with Asus a7n8x MB. 2-256 corsair 3500 ddr. I am using a Thermalright SLK800A heatsink with a Thermaltake 80mm 5000rpm fan that moves up to 70cfm for cooling. All in an aluminum case with 5 case fans. The problem is I am getting CPU temps in the upper 60's. Averaging about 68C just in the bios setup. The MB temp is 40 or more degree's cooler, running in the mid twenties. I though ok too much artic silver. I removed some and the temp shot up to 80C. I added more back on and am down to 68 again. How can I get this thing cooled down? Would a copper shim help? More arctic silver?
A few random thoughts; probably nothing you haven't already thought of/tried:
When you took the HS off, was there a solid imprint in the AS where the CPU is?
Does the cooler seem to be firmly on the CPU, or is it possible that it is not tight enough?
Is the cooler flat and square on the CPU, or is there a capacitor or anything holding it up?
If you lay the case down flat so that gravity isn't trying to pull the cooler off, does that help?
Have you tried flipping the fan over? You should probably be pushing air down onto the cooler, but even if you are you might want to test it the other way.
Yes. If you remove some Arctic Silver and the temps go up, you likely do not have it sitting flat on the CPU. Did you place those little feet in the wrong plce (might be sitting on something around the core). A capacitor in the way is possible. Also It might be possible it is on wrong (most heatsinks are notched out on the bottom to overhand the chip and still clear the socket on one end. The fan should be blowing into the heatsink, but that would only make a few degrees differance. It might be the heatsink base is warped or the clip is damaged.