why did my "solid state" 10 KV NST quit working?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jack Vandam" <snotoir7674g-at-mindspring-dot-com> 

A month ago, I had one of the newer "solid state" 10 KV NSTs.  I believe the
frequency output was on the order of 20Khz.  I thought that a transformer
like this might be ideal for feeding a high voltage multiplier, so I hooked
one up.  Within 30 seconds, the transformer went dead and has not been heard
from since.  I thought something might have tripped, so I looked around for
a reset switch but none found.  I tested the multiplier and it worked fine
with another drive source.  Any idea what could have gone wrong with this
NST?  Unfortunately, I couldn't open it as it's epoxied closed :(.

Thanks for any thoughts,
Jack