[Elecraft] Astron hum/vibration

[Barry]

I have an Astron RS70M linear supply that I've used for many years to 
power everything 12VDC in the shack, including my K3.  In my former QTH, 
I had it located under the operating desk and never heard a peep from it.

In my new shack, which is considerably smaller, I hear an annoying hum 
from it which seems to be coming from the top of the case.  It goes away 
if I press down on it.  Any ideas how to get rid of the noise?
Tnx,
Barry W2UP