Thermal paste etc nothing to do with beeping.
Sounds to me like the error it throws when a power cable has been forgotten to be plugged into the GPU........
As a test open the case, unplug any power cables going to the gpu, probably 2 x 6 pins im guessing?
try using other matching cables from psu if available, if not as I say unplug, make sure no fluff balls or anything, plug em back in and test it again.