Ken,
X-Ray is ususlly useless for looking for shorts in ceramic capacitors.
Ceramic capacitors are made of bariu which is a dandy X-Ray absorber.
Internal defects suck as small cracks will be invisable to X-Ray but can
still lead to low impedance conditions if no external dendrites are
formed. All that is needed is a low DC voltage >.86V,m a little humidity
and time for internal defects to short. High impedance keeps the part
from self destructing. Applying heat, typically with a soldering iron
only temporally closes internal defects and any conduction paths that may
have developed. The flaw and failure will show up again later. Contact me
off line if you have any further questions.

John Maxwell
PH: 719-687-6911
FAX: 719-687-8089
E-mail: [log in to unmask]

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